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Introduction: The leaf-height-seed (LHS) plant ecology strategy scheme posits that functional traits such as leaf size, stem height and seed mass play a key role in life history of plants. Although many studies have explored the LHS scheme across plant species, to our knowledge, no study has so far linked functional trait patterns across different plant clades. Methods: Here, we first explored the LHS scheme of several plant clades, i.e., palms, other monocots, dicots and gymnosperms, to understand how potential forces drive variation of plant functional traits. Results: We showed that phylogeny constrains plant functional traits and appears to be the most decisive factor that controls variation in seed mass irrespective of plant clades. Apart from phylogeny, a majority of variation in seed mass was explained by leaf size in palms clade, whereas by plant height in other monocots and dicots. Neither leaf size nor plant height well explained variation in seed mass of gymnosperms clade. Conclusion: Our study strongly suggests that different plant clades exhibit distinct LHS schemes, paving a new avenue for better understanding evolution and correlation between functional traits across sets of plant species. [ABSTRACT FROM AUTHOR]

The comprehension of the evolutionary mechanisms behind chloroplasts is derived from the comparative analysis of chloroplast (CP) genomes across various species. It sheds light on implementing molecular modifications and enhancing the efficacy of chloroplasts. In this study, we classified the chloroplast genomes of 12 organisms into monocots, dicots, and two C3 and C4 subgroups. Groups are as follows: 1. Dicots, C3; 2. Dicots, C4; 3. monocot, C4; and 4. monocot and C3. Following that, we conducted a comparative genomic analysis. Despite having differing mechanisms for carbon fixation, our findings revealed that there is 82% gene organization similarity between the dicot and monocot groups. In comparison, the estimated values for the C4 and C3 groups were 62% and 57%, respectively. The variation across the four groups is the result of several chromosomal rearrangements, particularly in the 9000 to 36,000 bp of the CP genomes. Additionally, GC content comparisons among the groups revealed that monocots have a greater GC content than dicots. We also discovered that 81% of simple sequence repeats were located in non-coding areas. Finally, our findings indicated that the amino acids in CP proteomes generally follow an identical pattern, particularly codons that follow a similar pattern for RSCU in all CP genomes. To summarize, our finding demonstrated that the assessment of CP genomes is a prerequisite for genetic modification and horizontal transfer of chloroplast genomes between plant species. [ABSTRACT FROM AUTHOR]

IntroductionThe leaf-height-seed (LHS) plant ecology strategy scheme posits that functional traits such as leaf size, stem height and seed mass play a key role in life history of plants. Although many studies have explored the LHS scheme across plant species, to our knowledge, no study has so far linked functional trait patterns across different plant clades.MethodsHere, we first explored the LHS scheme of several plant clades, i.e., palms, other monocots, dicots and gymnosperms, to understand how potential forces drive variation of plant functional traits.ResultsWe showed that phylogeny constrains plant functional traits and appears to be the most decisive factor that controls variation in seed mass irrespective of plant clades. Apart from phylogeny, a majority of variation in seed mass was explained by leaf size in palms clade, whereas by plant height in other monocots and dicots. Neither leaf size nor plant height well explained variation in seed mass of gymnosperms clade.ConclusionOur study strongly suggests that different plant clades exhibit distinct LHS schemes, paving a new avenue for better understanding evolution and correlation between functional traits across sets of plant species.

In this review, we explore the origin of the rudimentary embryo, its relationship to other kinds of plant embryos and its role in the diversification of angiosperms. Rudimentary embryos have a length:width ratio of ≤2.0, and they have organs, including cotyledon(s) and a primary root. A literature survey failed to reveal rudimentary embryos in the pre-angiosperms, suggesting that this kind of embryo is an angiosperm invention. Although proembryos of some gymnosperms and angiosperms have a length:width ratio of ≤2.0, they have not formed meristems or organs. Thus, rudimentary embryos are not proembryos. During the development of rudimentary embryos in monocots and dicots (all non-monocots), the growth pattern of the epicotyledonary cells differs, resulting in differences in the placement of the shoot meristem and in one versus two cotyledons, respectively, but the embryo size is similar. Rudimentary embryos grow inside the seed prior to germination, which is true for linear-underdeveloped embryos, including those in some gymnosperms. Rudimentary embryos served as the starting point for the great diversification of embryos, and ultimately of seeds, in angiosperms, and they are still present in many families of extant angiosperms. The rudimentary embryo is part of the syndrome of changes, including increased speed of pollen germination and pollen tube growth, simplification of the female gametophyte, development of endosperm and elimination of multiple embryo production from each zygote, that distinguish angiosperm seed production from that of gymnosperms. We conclude that the rudimentary embryo was one of many new developments of angiosperms that contributed to their great success on earth. [ABSTRACT FROM AUTHOR]

The leaf pigment complex traits of 44 wetland plant species from the Middle Urals (Russia) were studied to analyze their diversity in relation to taxonomy and life forms. The chlorophyll content per dry weight (ChlDW) and leaf area (ChlArea), the ratio of chlorophylls a and b, and CO2 uptake rates (ADW) were determined. ChlDW varied by 10-fold from 2.20 to 21.9 mg g−1 among the wetland plant species. The influence of taxonomy at the level of classes on the variation of the pigment complex traits was revealed. Dicots had greater ChlDW and had a greater proportion of chlorophylls in the light-harvesting complex (ChlLHC) than monocots. In dicots, ChlLHC was positively correlated with leaf area ratio (r = 0.63, p < 0.01), and the effect of life forms on the content and ratio of pigments was determined. In monocots, chlorophyll content was positively correlated with ADW (r = 0.75, p < 0.001) and plant height (r = 0.66, p < 0.001). In monocots, the effect of families on the pigment content was observed. The lack of differences in ChlArea between the different systematic groups and life forms indicates a similar ability of the leaf area unit to absorb a solar energy. [ABSTRACT FROM AUTHOR]

Iron (Fe) is an essential micronutrient for plant growth and development. Fe availability affects crops' productivity and the quality of their derived products and thus human nutrition. Fe is poorly available for plant use since it is mostly present in soils in the form of insoluble oxides/hydroxides, especially at neutral to alkaline pH. How plants cope with low-Fe conditions and acquire Fe from soil has been investigated for decades. Pioneering work highlighted that plants have evolved two different strategies to mine Fe from soils, the so-called Strategy I (Fe reduction strategy) and Strategy II (Fe chelation strategy). Strategy I is employed by non-grass species whereas graminaceous plants utilize Strategy II. Recently, it has emerged that these two strategies are not fully exclusive and that the mechanism used by plants for Fe uptake is directly shaped by the characteristics of the soil on which they grow (e.g., pH, oxygen concentration). In this review, recent findings on plant Fe uptake and the regulation of this process will be summarized and their impact on our understanding of plant Fe nutrition will be discussed. [ABSTRACT FROM AUTHOR]

Abstract Background Legume species are an important plant model because of their protein-rich physiology. The adaptability and productivity of legumes are limited by major biotic and abiotic stresses. Responses to these stresses directly involve plasma membrane receptor proteins known as receptor-like kinases and receptor-like proteins. Evaluating the homology relations among RLK and RLP for seven legume species, and exploring their presence among synteny blocks allow an increased understanding of evolutionary relations, physical position, and chromosomal distribution in related species and their shared roles in stress responses. Results Typically, a high proportion of RLK and RLP legume proteins belong to orthologous clusters, which is confirmed in this study, where between 66 to 90% of the RLKs and RLPs per legume species were classified in orthologous clusters. One-third of the evaluated syntenic blocks had shared RLK/RLP genes among both legumes and non-legumes. Among the legumes, between 75 and 98% of the RLK/RLP were present in syntenic blocks. The distribution of chromosomal segments between Phaseolus vulgaris and Vigna unguiculata, two species that diverged ~ 8 mya, were highly similar. Among the RLK/RLP synteny clusters, seven experimentally validated resistance RLK/RLP genes were identified in syntenic blocks. The RLK resistant genes FLS2, BIR2, ERECTA, IOS1, and AtSERK1 from Arabidopsis and SLSERK1 from Solanum lycopersicum were present in different pairwise syntenic blocks among the legume species. Meanwhile, only the LYM1- RLP resistant gene from Arabidopsis shared a syntenic blocks with Glycine max. Conclusions The orthology analysis of the RLK and RLP suggests a dynamic evolution in the legume family, with between 66 to 85% of RLK and 83 to 88% of RLP belonging to orthologous clusters among the species evaluated. In fact, for the 10-species comparison, a lower number of singleton proteins were reported among RLP compared to RLK, suggesting that RLP positions are more physically conserved compared to RLK. The identification of RLK and RLP genes among the synteny blocks in legumes revealed multiple highly conserved syntenic blocks on multiple chromosomes. Additionally, the analysis suggests that P. vulgaris is an appropriate anchor species for comparative genomics among legumes.

This promoter can also be used to drive nCas9 variant-mediated ABEs, such as ABE-nCas9-NG and ABE-XNG-nCas9 to perform adenine base editing at some NG PAM loci in dicot plants. Keywords: Adenine base editors; dicots; CRISPR; EF1 promoter EN Adenine base editors dicots CRISPR EF1 promoter 5 7 3 01/11/23 20230101 NES 230101 Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas systems have revolutionized plant breeding. Using I pSlEF1 i -ABE-XNG-nCas I 9 i or I pSlEF1 i -ABE-nCas9-NG system, adenine base editing was attained at sites with relaxed NG PAMs such as the TGT PAM in Arabidopsis and AGA PAM in soybean. [Extracted from the article]

Abstract Background In plants, the plasma membrane is enclosed by the cell wall and anchors RLK and RLP proteins, which play a fundamental role in perception of developmental and environmental cues and are crucial in plant development and immunity. These plasma membrane receptors belong to large gene/protein families that are not easily classified computationally. This detailed analysis of these plasma membrane proteins brings a new source of information to the legume genetic, physiology and breeding research communities. Results A computational approach to identify and classify RLK and RLP proteins is presented. The strategy was evaluated using experimentally-validated RLK and RLP proteins and was determined to have a sensitivity of over 0.85, a specificity of 1.00, and a Matthews correlation coefficient of 0.91. The computational approach can be used to develop a detailed catalog of plasma membrane receptors (by type and domains) in several legume/crop species. The exclusive domains identified in legumes for RLKs are WaaY, APH Pkinase_C, LRR_2, and EGF, and for RLP are L-lectin LPRY and PAN_4. The RLK-nonRD and RLCK subclasses are also discovered by the methodology. In both classes, less than 20% of the total RLK predicted for each species belong to this class. Among the 10-species evaluated ~ 40% of the proteins in the kinome are RLKs. The exclusive legume domain combinations identified are B-Lectin/PR5K domains in G. max, M. truncatula, V. angularis, and V. unguiculata and a three-domain combination B-lectin/S-locus/WAK in C. cajan, M. truncatula, P. vulgaris, V. angularis. and V. unguiculata. Conclusions The analysis suggests that about 2% of the proteins of each genome belong to the RLK family and less than 1% belong to RLP family. Domain diversity combinations are greater for RLKs compared with the RLP proteins and LRR domains, and the dual domain combination LRR/Malectin were the most frequent domain for both groups of plasma membrane receptors among legume and non-legume species. Legumes exclusively show Pkinase extracellular domains, and atypical domain combinations in RLK and RLP compared with the non-legumes evaluated. The computational logic approach is statistically well supported and can be used with the proteomes of other plant species.

Iron (Fe) is an essential micronutrient for plant growth and development. Fe availability affects crops’ productivity and the quality of their derived products and thus human nutrition. Fe is poorly available for plant use since it is mostly present in soils in the form of insoluble oxides/hydroxides, especially at neutral to alkaline pH. How plants cope with low-Fe conditions and acquire Fe from soil has been investigated for decades. Pioneering work highlighted that plants have evolved two different strategies to mine Fe from soils, the so-called Strategy I (Fe reduction strategy) and Strategy II (Fe chelation strategy). Strategy I is employed by non-grass species whereas graminaceous plants utilize Strategy II. Recently, it has emerged that these two strategies are not fully exclusive and that the mechanism used by plants for Fe uptake is directly shaped by the characteristics of the soil on which they grow (e.g., pH, oxygen concentration). In this review, recent findings on plant Fe uptake and the regulation of this process will be summarized and their impact on our understanding of plant Fe nutrition will be discussed.

Background: Legume species are an important plant model because of their protein-rich physiology. The adaptability and productivity of legumes are limited by major biotic and abiotic stresses. Responses to these stresses directly involve plasma membrane receptor proteins known as receptor-like kinases and receptor-like proteins. Evaluating the homology relations among RLK and RLP for seven legume species, and exploring their presence among synteny blocks allow an increased understanding of evolutionary relations, physical position, and chromosomal distribution in related species and their shared roles in stress responses. Results: Typically, a high proportion of RLK and RLP legume proteins belong to orthologous clusters, which is confirmed in this study, where between 66 to 90% of the RLKs and RLPs per legume species were classified in orthologous clusters. One-third of the evaluated syntenic blocks had shared RLK/RLP genes among both legumes and non-legumes. Among the legumes, between 75 and 98% of the RLK/RLP were present in syntenic blocks. The distribution of chromosomal segments between Phaseolus vulgaris and Vigna unguiculata, two species that diverged ~ 8 mya, were highly similar. Among the RLK/RLP synteny clusters, seven experimentally validated resistance RLK/RLP genes were identified in syntenic blocks. The RLK resistant genes FLS2, BIR2, ERECTA, IOS1, and AtSERK1 from Arabidopsis and SLSERK1 from Solanum lycopersicum were present in different pairwise syntenic blocks among the legume species. Meanwhile, only the LYM1- RLP resistant gene from Arabidopsis shared a syntenic blocks with Glycine max. Conclusions: The orthology analysis of the RLK and RLP suggests a dynamic evolution in the legume family, with between 66 to 85% of RLK and 83 to 88% of RLP belonging to orthologous clusters among the species evaluated. In fact, for the 10-species comparison, a lower number of singleton proteins were reported among RLP compared to RLK, suggesting that RLP positions are more physically conserved compared to RLK. The identification of RLK and RLP genes among the synteny blocks in legumes revealed multiple highly conserved syntenic blocks on multiple chromosomes. Additionally, the analysis suggests that P. vulgaris is an appropriate anchor species for comparative genomics among legumes. [ABSTRACT FROM AUTHOR]

Background: In the almost century since the establishment of boron (B) as an essential plant nutrient, its roles in plant growth and development have been identified, and the mechanism for B transportation explained. Scope: This review relates the yield response of crops, measured as B efficiency i.e. productivity when B is limiting relative to when it is not, to the B supply logistics and requirement of different tissues and organs. Conclusions: Yield is depressed by B deficiency in graminaceous cereals primarily by impaired development and function of the stamen and pistil, but in dicots the adverse effects are expressed as structural damage to various organs. Boron-efficient cereal genotypes are readily identifiable by their successful grain set under limited B, while the quantitative trait loci associated with B efficiency provide a useful selection tool for dicots. The relevance to breeding for B efficiency of the numerous BOR1 and NIP genes controlling active B transport identified in many crops will depend on how close their up-regulation in a deficiency is associated with B efficiency. Understanding of the yield impact of B deficiency is useful in dealing with crop choice and the management of germplasm and B fertilizer. [ABSTRACT FROM AUTHOR]

Main conclusion: An improved CRISPR/Cas9 system with the Arabidopsis UBQ10 promoter-driven Cas9 exhibits consistently high mutation efficiency in Arabidopsis and M. truncatula. CRISPR/Cas9 is a powerful genome editing technology that has been applied in several crop species for trait improvement due to its simplicity, versatility, and specificity. However, the mutation efficiency of CRISPR/Cas9 in Arabidopsis and M. truncatula (Mt) is still challenging and inconsistent. To analyze the functionality of the CRISPR/Cas9 system in two model dicot species, four different promoter-driven Cas9 systems to target phytoene desaturase (PDS) genes were designed. Agrobacterium-mediated transformation was used for the delivery of constructed vectors to host plants. Phenotypic and genotypic analyses revealed that the Arabidopsis UBQ10 promoter-driven Cas9 significantly improves the mutation efficiency to 95% in Arabidopsis and 70% in M. truncatula. Moreover, the UBQ10-Cas9 system yielded 11% homozygous mutants in the T1 generation in Arabidopsis. Sequencing analyses of mutation events indicated that single-nucleotide insertions are the most frequent events in Arabidopsis, whereas multi-nucleotide deletions are dominant in bi-allelic and mono-allelic homozygous mutants in M. truncatula. Taken together, the UBQ10 promoter facilitates the best improvement in the CRISPR/Cas9 efficiency in PDS gene editing, followed by the EC1.2 promoter. Consistently, the improved UBQ10-Cas9 vector highly enhanced the mutation efficiency by four-fold over the commonly used 35S promoter in both dicot species. [ABSTRACT FROM AUTHOR]

Background: In plants, the plasma membrane is enclosed by the cell wall and anchors RLK and RLP proteins, which play a fundamental role in perception of developmental and environmental cues and are crucial in plant development and immunity. These plasma membrane receptors belong to large gene/protein families that are not easily classified computationally. This detailed analysis of these plasma membrane proteins brings a new source of information to the legume genetic, physiology and breeding research communities. Results: A computational approach to identify and classify RLK and RLP proteins is presented. The strategy was evaluated using experimentally-validated RLK and RLP proteins and was determined to have a sensitivity of over 0.85, a specificity of 1.00, and a Matthews correlation coefficient of 0.91. The computational approach can be used to develop a detailed catalog of plasma membrane receptors (by type and domains) in several legume/crop species. The exclusive domains identified in legumes for RLKs are WaaY, APH Pkinase_C, LRR_2, and EGF, and for RLP are L-lectin LPRY and PAN_4. The RLK-nonRD and RLCK subclasses are also discovered by the methodology. In both classes, less than 20% of the total RLK predicted for each species belong to this class. Among the 10-species evaluated ~ 40% of the proteins in the kinome are RLKs. The exclusive legume domain combinations identified are B-Lectin/PR5K domains in G. max, M. truncatula, V. angularis, and V. unguiculata and a three-domain combination B-lectin/S-locus/WAK in C. cajan, M. truncatula, P. vulgaris, V. angularis. and V. unguiculata. Conclusions: The analysis suggests that about 2% of the proteins of each genome belong to the RLK family and less than 1% belong to RLP family. Domain diversity combinations are greater for RLKs compared with the RLP proteins and LRR domains, and the dual domain combination LRR/Malectin were the most frequent domain for both groups of plasma membrane receptors among legume and non-legume species. Legumes exclusively show Pkinase extracellular domains, and atypical domain combinations in RLK and RLP compared with the non-legumes evaluated. The computational logic approach is statistically well supported and can be used with the proteomes of other plant species. [ABSTRACT FROM AUTHOR]

Analysis of root growth parameters was carried out on the seedlings of 53 monocotyledonous and 78 dicotyledonous plant species. Daily increases of the root length, the root diameter, the length of the meristematic and elongation zones, the length and the number of cells in a cell file of the meristematical cortex cells, and the length of the fully elongated cells were measured during the steady-state growth. From these parameters, such indices as root growth rate, the relative rates of cell division and elongation, rates of the cell production and transition to elongation, duration of the cell cycle and elongation were derived. Plants from different families were found to have a clear resemblance in the parameters determining the root growth at a cellular level. In the examined species, the difference in the root growth rate depended mainly on the difference in the cell number in a cell file within the meristem and, to a lesser extent, on the length of the cells that had completed growth and on the cell cycle duration. The length of the meristem and the number of meristematic cells in a cell file strongly correlated with the root diameter, whereas the relative growth rate of the meristematic and elongating cells and the duration of the elongation growth had weak correlation with the root diameter. [ABSTRACT FROM AUTHOR]

The monopole-dimer model introduced recently is an exactly solvable signed generalisation of the dimer model. We show that the partition function of the monopole-dimer model on a graph invariant under a fixed-point free involution is a perfect square. We give a combinatorial interpretation of the square root of the partition function for such graphs in terms of a monopole-dimer model on a new kind of graph with two types of edges which we call a dicot. The partition function of the latter can be written as a determinant, this time of a complex adjacency matrix. This formulation generalises Wu's assignment of imaginary orientation for the grid graph to planar dicots. As an application, we compute the partition function for a family of non-planar dicots with positive weights. [ABSTRACT FROM AUTHOR]

Inquiry- and course-based research pedagogies have demonstrated effectiveness for preparing undergraduate biology students with authentic scientific skills and competencies, yet many students lack the experience to engage successfully in open-ended research activities without sufficient scaffolding and structure. Further, curricula for student-centered laboratory activities are lacking for several biological disciplines, including plant biology and botany. In this article, I describe a semester-long structured-inquiry research curriculum developed for a plant biology course taught to second-year biology students that integrates key elements of inquiry and discovery while providing a structured approach to gaining research skills. In the research project, students collect leaves from woody dicot plants across a range of environments that are characterized by different mean annual temperatures, and investigate the relationship between various leaf characteristics and temperature. Curricular materials are provided to teach skills in scientific paper reading, field data collection, data processing including microscopy and image analysis, quantitative data analysis in R, biological inference, and scientific writing. This comprehensive, ready-to-implement curriculum is suitable for plant biology, botany, and plant ecology courses and is particularly valuable for students with no prior research experience. [ABSTRACT FROM AUTHOR]

Abstract Background The available data demonstrate that even in universal metabolic pathways, some species-specific regulatory features of structural genes are present. For instance, in the anthocyanin biosynthesis pathway (ABP), genes may be regulated by ABP-specific regulatory factors, and their expression levels may be strongly associated with anthocyanin pigmentation, or they may be expressed independently of pigmentation. A dataset of orthologous ABP genes (Chs, Chi, F3h, F3’h, Dfr, Ans) from monocot and dicot plant species that have distinct gene regulation patterns and different types of pollination was constructed to test whether these factors affect the evolution of the genes. Results Using a maximum likelihood approach, we demonstrated that although the whole set of the ABP genes is under purifying selection, with greater selection acting on the upstream genes than on the downstream genes, genes from distinct groups of plant species experienced different strengths of selective pressure. The selective pressure on the genes was higher in dicots than in monocots (F3h and further downstream genes) and in pollinator-dependent plants than in pollinator-independent species (Chi and further downstream genes), suggesting an important role of pollination type in the evolution of the anthocyanin biosynthesis gene network. Contrasting effects of the regulation patterns on evolution were detected for the F3h and Dfr genes, with greater selective pressure on the F3h gene in plant species where the gene expression was not strongly associated with pigmentation and greater selective pressure on Dfr in plant species where the gene expression was associated with pigmentation. Conclusions We demonstrated the effects of pollination type and patterns of regulation on the evolution of the ABP genes, but the evolution of some of the genes could not be explained in the framework of these factors, such as the weaker selective pressure acting on Chs in species that attract pollinators or the stronger selective pressure on F3h in plant species where the gene expression was not associated with pigmentation. The observations suggest that additional factors could affect the evolution of these genes. One such factor could be an effect of gene duplication with further division of functions among gene copies and relaxed selective pressure acting on them. Additional tests with an appropriate dataset combining data on duplicated gene sequences and their functions in the flavonoid biosynthesis pathway are required to test this hypothesis.

Questions: Ants and rodents are recognized as ecosystem engineers worldwide creating soil‐modified nests and adjacent edges with superior resources. The influence of Dipodomys spectabilis (rat) and Pogonomyrmex rugosus (ant) on nests and edges would be similar in burned and unburned habitat on functional groups' cover, density, number of inflorescences and species number. We hypothesize that annual and perennial dicots would recover faster on rat patches than on burned grassland, dicots and grasses would recover faster on ant patches than on burned grassland, and annual dicots would recover faster on rat than on ant patches, whereas grasses would recover faster on ant than on rat patches. Location: Semiarid grassland, Sevilleta National Wildlife Refuge, New Mexico, USA. Methods: We analyzed annual and perennial dicots, grasses and subshrubs in burned and unburned plots at 80 nests during cool‐ and warm‐seasons two years post‐fire. Data were collected at nest top (mound), edge, and 20 m (control) from the edge. Results: Cover, density and species richness of different functional groups were low on animal mounds in unburned and burned plots. Ant edges had greater perennial dicot cover, grass cover and richness while rat edges had lower grass density and richness than control sites at unburned and burned plots. Perennial dicot density and richness recovered faster at rat mounds and edges than control. Ant edges yielded faster recovery of grass inflorescences than control. Dicots recovered faster on rat than ant mounds whereas grasses grew faster on ant edges. Conclusions: Rats create nests enhancing density of recovering dicots and ant edges facilitate reproduction of recovering grasses. Equal regeneration between animal nests and grassland occurred commonly when fire reduced grass competition. Dysochory, granivory and fire intensity may influence recovery. Nests may be sources of reestablishment and seed dispersal. Recovery of grassland may be amplified as plants infill from engineered nests. [ABSTRACT FROM AUTHOR]

Jasmonates are important phytohormones involved in both plant developmental processes as well as defense reactions. Many JA-mediated plant defense responses have been studied in model plants using mutants of the jasmonate signaling pathway. However, in plant species where JA-signaling mutants are not accessible, the availability of a tool targeting JA signaling is crucial to investigate jasmonate-dependent processes. Neomycin is a poly-cationic aminoglycoside antibiotic that blocks the release of Ca2+ from internal stores. We examined the inhibitory activities of neomycin on different jasmonate-inducible responses in eight different plant species: Intracellular calcium measurements in Nicotiana tabacum cell culture, Sporamin gene induction in Ipomoea batatas, PDF2.2 gene expression in Triticum aestivum, Nepenthesin protease activity measurement in Nepenthes alata, extrafloral nectar production in Phaseolus lunatus, nectary formation in Populus trichocarpa, terpene accumulation in Picea abies, and secondary metabolite generation in Nicotiana attenuata. We are able to show that neomycin, an easily manageable and commercially available compound, inhibits JA-mediated responses across the plant kingdom. [ABSTRACT FROM AUTHOR]

Fungal necrosis and ethylene inducing proteins (NEPs) induce cell death and elicit strong immune responses in many crops. In this study, we report the cloning and characterization of a transcript encoding NEP from Ganoderma boninense which belongs to a family of fungi in Ganodermataceae that cause serious infections of cacao, rubber, tea, coffee and palms. The open reading frame (ORF) encoding NEP in G. boninense (GbNEP) was cloned by 5′ and 3' rapid amplification of cDNA ends (RACE) PCR. The transcript abundance of GbNEP increased in fungal culture treated with salicylic acid and jasmonic acid, respectively. The soluble recombinant GbNEP expressed in Escherichia coli BL21(DE3)pLysS was able to induce necrosis in tobacco and tomato but ineffective when applied to oil palm leaves and root tissues. The recombinant GbNEP could induce localized cell death, and production of hydrogen peroxide and superoxide in tobacco leaves. The addition of LaCl 3 (a calcium channel inhibitor) and EGTA (a Ca2+ chelator) to tobacco leaves prior to the challenge with GbNEP significantly reduced the necrosis symptoms indicating that Ca2+ is required for the action of GbNEP. In summary, this is the first report of NEP from Ganoderma species which may contribute to further research on the role of GbNEP during disease development. • First report of necrosis and ethylene inducing protein (NEP) from Ganoderma boninense. • The transcript abundance of GbNEP increased in G. boninense culture treated with salicylic acid and jasmonic acid, respectively. • Soluble recombinant GbNEP was able to induce necrosis in tobacco and tomato but ineffective when applied to oil palm leaves and root tissues. • Recombinant GbNEP could induce defense responses in tobacco leaves. • Calcium is required for the action of GbNEP. [ABSTRACT FROM AUTHOR]

Leaf senescence is a destructive process that allows the efficient recycling of nutrients from dying leaves to growing parts of the plant. It is the final stage of leaf development that can be induced in response to stress. This makes leaf senescence an adaptive process that is highly beneficial for whole plant survival under unpredictable environmental conditions. Thus, the manipulation of this process has the potential to improve crop plants to become more climate resilient. In this review we compare leaf senescence processes between distantly related species to identify knowledge gaps and opportunities for plant improvement strategies. We describe that main signalling pathways controlled by carbohydrates, reactive oxygen species and hormones are conserved. However, the role of ethylene in age-induced leaf senescence in cereals is obscure. Moreover, downstream senescence regulatory signalling events are largely unknown, and these may be considerably different between members of annual dicots and cereals. Because leaf senescence regulation is so intricately connected to basic metabolic and developmental processes, we propose to increase research efforts to discover natural variation in senescence regulation and pinpoint gene variants that are tried and tested in nature. • Leaf senescence is an important nutrient recovery programme in a wide range of plant species. • Plant development and stress regulate leaf senescence. • Phytohormones and oxidative stress play similar roles in the induction of senescence in dicots and cereals. • Downstream signalling events often differ between dicots and cereals. • Harnessing natural variation in senescence regulatory genes can improve crop yield. [ABSTRACT FROM AUTHOR]

Searching for new bio-based herbicides is crucial for decreasing chemical pollution, protecting the environment, and sustaining biodiversity. Origanum vulgare is considered a promising source of essential oil with herbicidal effect. The mode of action is not known. The present study focused on (1) comparison of phytotoxic activity of Origanum vulgare EO on monocot (Triticum aestivum and Hordeum vulgare) and dicot species (Lepidium sativum and Sinapis alba); (2) and evaluating other antimicrobial biological activities against phytopatogen bacteria (Clavibacter michiganensis, Pseudomonas syringae pv. phaseolicola, Pseudomonas savastanoi, and Xanthomonas campestris); antifungal activity against Monilinia fructicola, Aspergillus niger, Penicillium expansum, and Botrytis cinerea; cytotoxic activity and antioxidant activity. According to the GC/MS analyses, the EO belongs to the thymol chemotype O. vulgare with its high content of thymol (76%). Germination of all four species was not influenced by EO. The phytotoxic effect was statistically significant in the monocot species, while in the dicot species the opposite was observed—a stimulation effect, which was also statistically significant. Strong biological activity of O. vulgare EO was noted on all phytopatogen bacteria and fungi in the highest dose. Cytotoxic activity showed an IC50 = 50.5 μg/mL. Antioxidant activity showed an IC50 = 106.6 μg/mL after 45 min experimental time. Based on the presented results, it is possible to conclude that thymol chemotype O. vulgare essential oil could be potentially used as a herbicide with selective effects on monocot plant species.

Graphical abstract Highlights • AMF colonization is lower in wetland-aquatic habitats than in the terrestrial ones. • In monocots AMF colonization is lower at both the species and family levels. • The hydrological conditions are negatively correlated with AMF colonization. • AMF colonization tends to be low in obligate wetland plants. • AMF association is not-always an advantageous trait in aquatic habitats. Abstract Plants that live in aquatic habitats are frequently subjected to oxygen limitation and many of them modify their anatomy and physiology to counteract hypoxia. In these habitats, the role of plant associations with arbuscular mycorrhizal fungi (AMF), which are widespread in terrestrial environments and frequently confer benefits to the associated plant, is still debated. Starting from data taken from 34 selected papers, this study focuses on the occurrence of AMF in the roots of wetland and aquatic plants, taking into account the hydrological conditions of the sites, the plant wetland indicators and life forms, plant taxonomy and colonization by dark septate endophytes. The results have demonstrated the importance of hydrology in controlling the frequency and intensity of AMF root colonization, which tends to be low in obligate wetland plants. Moreover, colonization is generally lower and, possibly, less functional in monocots than in dicots. We suggest that the hydrological conditions, by filtering species according to their water tolerance, shape plant community composition, and that although AMF colonization is one of the traits that may increase plant fitness, it is not the most important one. In fact, a range of nutritional and growth strategies, which are more variegated than in terrestrial habitats, exists in wetland/aquatic habitats, and these strategies may rely, or not, on AMF colonization, as a consequence of the habitat and species. [ABSTRACT FROM AUTHOR]

Since last decade, GSM (Global System for Mobile Communication) technology has evidently revolutionized our digital world. It uses electromagnetic frequency radiations (EMFr), ranging 850-1900 MHz, and is being composed of three main units (i.e., mobile station, access and core networks). GSM technology has significant impact on our daily life as revealed by increased number of mobile users in the world over. The main goal of the present review is to critically revisit the available literature regarding the responses of various flowering plant species towards GSM and GSM-like radiations using physiological, biochemical, molecular and cytological markers using in vitro approaches. Different monocots (tomato, onion, wheat and maize etc.) and dicots (pulses, mustard and flax) have been studied using both GSM mobile phone and GSM simulators. Different studies revealed overall reductions in germination, root-shoot lengths, dry weight, in both dose and time-dependent manners. However, there could be found incline in various parameters at biochemical and molecular levels. Furthermore, there could be found disturbances at cytological levels upon exposure of roots of onion to EMFr radiations. The overall literature review shows the negative effects of GSM and GSM-like radiations on targeted plant species. In order to alleviate the stressful effects of EMFr radiations on plants, in vivo studies need to be done using various cost-effective approaches such as use of biochar and various organic amendments. [ABSTRACT FROM AUTHOR]

Abstract: Plant variation in nutrient concentrations encompasses two major axes. The first is connected to nitrogen (N) and phosphorus (P), reflects growth rate and has been designated as the leaf economics spectrum (LES) while the second follows the gradient in calcium (Ca) and magnesium (Mg) and mirrors cell structural differences. Here, we tested in grasslands whether the sum Ca + Mg concentrations is a better indicator of digestibility than LES constituents. Structural equation modelling revealed that the total effect size of N (0.30) on digestibility was much lower than that of Ca + Mg (0.58). The N effect originated predominantly from sampling date (biomass ageing), while the Ca + Mg effect largely from phylogenetic composition (proportion of monocots). Thus, plant variation in partially substitutable divalent cations seems to play a significant role in biomass digestion by ruminants. This finding contests, together with litter decomposition studies, the prominent role of the LES for understanding both fundamental ecological processes. [ABSTRACT FROM AUTHOR]

Primary roots of 98 species from different families of monocotyledonous and dicotyledonous plants and adventitious roots obtained from bulbs and rhizomes of 24 monocot species were studied. Root growth rate, root diameter, length of the meristem and elongation zones, number of meristematic cells in a file of cortical cells, and length of fully elongated cells were evaluated in each species after the onset of steady growth. The mitotic cycle duration and relative cell elongation rate were calculated. In all species, the meristem length was approximately equal to two root diameters. When comparing different species, the rate of root growth increased with a larger root diameter. This was due to an increase in the number of meristematic cells in a row and, to a lesser degree, to a greater length of fully elongated cells. The duration of the mitotic cycle and the relative cell elongation rate did not correlate with the root diameter. It is suggested that the meristem size depends on the level of nutrient inflow from upper tissues, and is thereby controlled during further growth. [ABSTRACT FROM AUTHOR]

Long non-coding RNAs (lncRNAs) are gene regulators that have vital roles in development and adaptation to the environment in eukaryotes. However, the structural and evolutionary analyses of plant lncRNAs are limited. In this study, we performed an analysis of lncRNAs in five monocot and five dicot species. Our results showed that plant lncRNA genes were generally shorter and had fewer exons than protein-coding genes. The numbers of lncRNAs were positively correlated with the numbers of protein-coding genes in different plant species, despite a high range of variation. Sequence conservation analysis showed that the majority of lncRNAs had high sequence conservation at the intra-species and sub-species levels, reminiscent of protein-coding genes. At the inter-species level, a subset of lncRNAs were highly diverged at the nucleotide level, but conserved by position. Interestingly, we found that plant lncRNAs have identical splicing signals, and those which can form precursors or targets of miRNAs have a conservative identity in different species. We also revealed that most of the lowly expressed lncRNAs were tissue-specific, while those highly conserved were constitutively transcribed. Meanwhile, we characterized a subset of rice lncRNAs that were co-expressed with their adjacent protein-coding genes, suggesting they may play cis-regulatory roles. These results will contribute to understanding the biological significance and evolution of lncRNAs in plants. [ABSTRACT FROM AUTHOR]

Background: The available data demonstrate that even in universal metabolic pathways, some species-specific regulatory features of structural genes are present. For instance, in the anthocyanin biosynthesis pathway (ABP), genes may be regulated by ABP-specific regulatory factors, and their expression levels may be strongly associated with anthocyanin pigmentation, or they may be expressed independently of pigmentation. A dataset of orthologous ABP genes (Chs, Chi, F3h, F3'h, Dfr, Ans) from monocot and dicot plant species that have distinct gene regulation patterns and different types of pollination was constructed to test whether these factors affect the evolution of the genes. Results: Using a maximum likelihood approach, we demonstrated that although the whole set of the ABP genes is under purifying selection, with greater selection acting on the upstream genes than on the downstream genes, genes from distinct groups of plant species experienced different strengths of selective pressure. The selective pressure on the genes was higher in dicots than in monocots (F3h and further downstream genes) and in pollinator-dependent plants than in pollinator-independent species (Chi and further downstream genes), suggesting an important role of pollination type in the evolution of the anthocyanin biosynthesis gene network. Contrasting effects of the regulation patterns on evolution were detected for the F3h and Dfr genes, with greater selective pressure on the F3h gene in plant species where the gene expression was not strongly associated with pigmentation and greater selective pressure on Dfr in plant species where the gene expression was associated with pigmentation. Conclusions: We demonstrated the effects of pollination type and patterns of regulation on the evolution of the ABP genes, but the evolution of some of the genes could not be explained in the framework of these factors, such as the weaker selective pressure acting on Chs in species that attract pollinators or the stronger selective pressure on F3h in plant species where the gene expression was not associated with pigmentation. The observations suggest that additional factors could affect the evolution of these genes. One such factor could be an effect of gene duplication with further division of functions among gene copies and relaxed selective pressure acting on them. Additional tests with an appropriate dataset combining data on duplicated gene sequences and their functions in the flavonoid biosynthesis pathway are required to test this hypothesis. [ABSTRACT FROM AUTHOR]

We used comparative methods that account for the phylogenetic correlations among species to test hypotheses about the community of gall-inducing insects on dicotyledonous and monocotyledonous plants and woody and herbaceous angiosperms in the UK. We found that the species richness of gall-inducing insects on dicots was greater than on monocots and that the odds of a dicot having an associated gall-inducing insect is 42% higher than for a monocot. Woody angiosperms have higher species richness of associated gall-inducing insects than do herbaceous angiosperms. Furthermore, using a Monte Carlo analysis we found that attacks by gall-inducing insects on monocot families were phylogenetically clustered in the order Poales, particularly within the grass family Poaceae. We suggest that the higher risk of attack on dicots and higher species richness of gall-inducing insects on woody angiosperms, which are exclusively dicots, arises because of differences in the abundance or susceptibility of dicot meristems to attack by gall-inducing insects. Architectural and anatomical differences between monocots and dicots that give rise to differences in meristem abundance and anatomy appear to play an important role in determining the occurrence and richness of associated gall-inducing insects on host plants. [ABSTRACT FROM AUTHOR]

Unreduced gametes play a fundamental role in speciation of flowering plants, asexual reproduction of plants, and restoration of fertility of distant hybrids used to produce new varieties with breeding-valuable traits. Unreduced gametes are formed as a result of meiotic restitution. To date, a large body of data has been accumulated on the types of meiotic restitution in dicots and monocots. However, there is no clear idea on the cytological mechanisms of this process. In this review, we systematize and analyze all currently known mechanisms of restitution in plants. New data on the mechanisms and genetic regulation of unreduced gamete formation in intergeneric wheat hybrids are presented. [ABSTRACT FROM AUTHOR]

This study evaluated the allelopathic effect of theHesperozygis ringensessential oil using dicotyledonous and monocotyledonous seeds which are classified as weeds [Bidens pilosaandLolium multiflorum], bioindicators [Lactuca sativaandAvena strigosa] and crops [Glycine maxandOryza sativa]. The essential oil from the leaves was extracted and analyzed by gas chromatography coupled to mass spectrometry and gas chromatography with flame ionization detector. The extractive was diluted in ethanol, Tween 20 and water, and then tested at concentrations of 0.25, 0.50, 1.00, 2.50, and 5.00% (v/v). Water and the highest concentration of the solvents were used as control groups. The analyzed variables were germination, emergence velocity index, roots and shoot lengths and total seedlings length. Pulegone was the major essential oil compound representing 82.02% of the composition. Considering dicot seeds, the highest concentration of the extractive completely inhibited the germination ofBidens pilosawithout affecting the germination ofLactuca sativaandGlycine max. On monocots, the highest essential oil concentration affected the germination ofLolium multiflorumandAvena strigosawithout affecting theOryza sativaone. The results indicate that the extractive has the potential to control weeds because they were more affected than the crops. [ABSTRACT FROM PUBLISHER]

Background: In recent years, the damage caused by bacterial pathogens to major crops has been increasing worldwide. Pseudomonas syringae is a widespread bacterial species that infects almost all major crops. Different P. syringae strains use a wide range of biochemical mechanisms, including phytotoxins and effectors of the type III and type IV secretion systems, which determine the specific nature of the pathogen virulence. Results: Strains 1845 (isolated from dicots) and 2507 (isolated from monocots) were selected for sequencing because they specialize on different groups of plants. We compared virulence factors in these and other available genomes of phylogroup 2 to find genes responsible for the specialization of bacteria. We showed that strain 1845 belongs to the clonal group that has been infecting monocots in Russia and USA for a long time (at least 50 years). Strain 1845 has relatively recently changed its host plant to dicots. Conclusions: The results obtained by comparing the strain 1845 genome with the genomes of bacteria infecting monocots can help to identify the genes that define specific nature of the virulence of P. syringae strains. [ABSTRACT FROM AUTHOR]

The lengths of meristematic ( l ) and fully-elongated cells ( l ) were measured in the roots of 118 monocot and dicot species of herbaceous plants from 20 angiosperm families. The results were analyzed using the data on haploid DNA content ( C ) for the same species from the website (http://data.kew.org/cvalues). The distribution range of l , l , and C was wider in monocot plants compared to dicots. Values of l and l in monocot and l in dicot species correlated positively with C . Dependence of l and l on C was similar in diploid and polyploid species, both monocots and dicots. The average length of root cells differed less than the root length. [ABSTRACT FROM AUTHOR]

Cell walls are a distinguishing characteristic of plants essential to their survival. The pectin content of primary cell walls in grasses and dicots is distinctly different. Polygalacturonases (PGs) can degrade pectins and participate in multiple developmental processes of plants. This study comprehensively compared the evolution, expression, and cis-regulatory element of PGs in grasses and dicots. A total of 577 PGs identified from five grasses and five dicots fell into seven clades. Evolutionary analysis demonstrated the distinct differences between grasses and dicots in patterns of gene duplication and loss, and evolutionary rates. Grasses generally contained much fewer clade C and F members than dicots. We found that this disparity was the result of less duplication and more gene losses in grasses. More duplications occurred in clades D and E, and expression analysis showed that most of clade E members were expressed ubiquitously at a high overall level and clade D members were closely related to male reproduction in both grasses and dicots, suggesting their biological functions were highly conserved across species. In addition to the general role in reproductive development, PGs of clades C and F specifically played roles in root development in dicots, shedding light on organ differentiation between the two groups of plants. A regulatory element analysis of clade C and F members implied that possible functions of PGs in specific biological responses contributed to their expansion and preservation. This work can improve the knowledge of PGs in plants generally and in grasses specifically and is beneficial to functional studies. [ABSTRACT FROM AUTHOR]

Nucleotide distribution around translation initiation site (TIS) is thought to play an important role in determining translation efficiency. Kozak in vertebrates and later Joshi et al. in plants identified context sequence having a key role in translation efficiency, but a great variation regarding this context sequence has been observed among different taxa. The present study aims to refine the context sequence around initiation codon in plants and addresses the sampling error problem by using complete genomes of 7 monocots and 7 dicots separately. Besides positions −3 and +4, significant conservation at −2 and +5 positions was also found and nucleotide bias at the latter two positions was shown to directly influence translation efficiency in the taxon studied. About 1.8% (monocots) and 2.4% (dicots) of the total sequences fit the context sequence from positions −3 to +5, which might be indicative of lower number of housekeeping genes in the transcriptome. A three base periodicity was observed in 5′ UTR and CDS of monocots and only in CDS of dicots as confirmed against random occurrence and annotation errors. Deterministic enrichment of GCN AUG GC in monocots, AAN AUG GC in dicots and GCN AUG GC in plants around TIS was also established (where AUG denotes the start codon), which can serve as an arbiter of putative TIS with efficient translation in plants. [ABSTRACT FROM AUTHOR]

Background: Intronless genes are a significant characteristic of prokaryotes. Systematic identification and annotation are primary and crucial steps for determining the functions of intronless genes and understanding their occurrence in eukaryotes. Description: In this paper, we describe the construction of the Intronless Genes Database in Dicots (IGDD; available at http://bio.njfu.edu.cn/igdd/), which contains data for five well-annotated plants including Arabidopsis thaliana, Carica papaya, Populus trichocarpa, Salix suchowensis and Vitis vinifera. Using highly visual settings, IGDD displays the structural and functional annotations, the homolog groups, the syntenic relationships, the expression patterns, and the statistical characteristics of intronless genes. In addition, useful tools such as an advanced search and local BLAST are available through a user-friendly and intuitive web interface. Conclusion: In conclusion, the IGDD provides a comprehensive and up-to-date platform for researchers to assist the exploration of intronless genes in dicot plants. [ABSTRACT FROM AUTHOR]

Despite the importance of mycorrhizal symbiosis, we understand little how different soil managements affect arbuscular mycorrhizal fungi (AMF) communities. Crop rotation is recommended in sustainable agriculture because of its benefits in soil fertility improvement and positive effect decreasing soil borne diseases incidence and pest abundance. Amplicon sequencing of LSU and SSU rRNA gene fragments was used to analyse AMF diversity in fields from one of the most productive regions in Argentina, which varied in the main class of the plant component included in the crop rotation scheme. The samples encompassed different agricultural settings; one involving only monocot plants in the crop rotation schemes, one including a dicot crop, and the other an alternation and/or a combination of monocot and dicot plant components. We found lower richness and diversity in soils under monocot succession than in a dicot/monocot rotation or consociation. We observed that agricultural management had an influence on beta diversity patterns. Principal coordinate analysis showed that communities from the dicot/monocot rotation or consociation samples clustered together and separated from the monocots samples. These findings suggested that the increment of soil AMF diversity is more dependent on the alternation between monocot and dicot crops than other factors related to the farming systems. [ABSTRACT FROM AUTHOR]

Background: A screening method for elicitor and priming agents does not only allow detecting new bioactive substances, it can also be used to understand structure-function relationships of known agents by testing different derivatives of them. This can not only provide new lead compounds for the development of novel, more environment- benign, bio-based agro-chemicals, it may eventually also lead to a better understanding of defense mechanisms in plants. Reactive oxygen species (ROS) are sensitive indicators of these mechanisms but current assay formats are not suitable for multiplex screening, in particularly not in the case of monocot systems. Results: Here we describe continuous monitoring of ROS in 96-well microtiter plates using the chemiluminescent probe L012, a luminol derivative producing chemiluminescence when oxidised by ROS like hydrogen peroxide, superoxide, or hydroxyl radical that can thus be used as an indicator for these ROS. We were able to measure ROS in both monocot (Oryza sativa) and dicot (Medicago truncatula) cell suspension cultures and record dose dependencies for the carbohydrate elicitors and priming agents ulvan and chitosan at low substrate concentrations (0.3-2.5 µg/ml). The method was optimized in terms of cell density, L012 concentration, and pre-incubation time. In contrast to the single peak observed using a cuvette luminometer, the improved method revealed a double burst in both cell systems during the 90-min measuring period, probably due to the detection of multiple ROS rather than only H2O2. Conclusion: We provide a medium throughput screening method for monocot and dicot suspension-cultured cells that enables direct comparison of monocot and dicot plant systems regarding their reaction to different signaling molecules. [ABSTRACT FROM AUTHOR]

• Modèle mathématique de phyllotaxie. • Détermination de la disposition des sépales par celle de la bractée et des bractéoles. • Modélisation de tous les cas de disposition des sépales (monocots et dicots) décrits par Eichler (1875). Eichler (1875) hypothesized that the position of the bracteoles determines the position of sepals and made a near-exhaustive list of the different arrangements found in monocots and dicots. However, he was unable to provide a theoretical basis for these observations. Eichler's hypothesis has not had much success over the past 150 years. In this study, we find that the classical mathematical theory of phyllotaxy makes it possible to model all the arrangements listed by Eichler from the angular and radial positions of the bracteoles and subtending bracts. [ABSTRACT FROM AUTHOR]

Plant microRNAs (miRNAs), a class of small non-coding regulatory RNAs, are canonically 20–24 nucleotides (nt) in length and bind to complementary target RNA sequences, guiding target attenuation via mRNA degradation or translation inhibition. Of the annotated miRNA families, evolutionarily conserved families have been well known to extensively regulate analogous targets and play critical roles in plant development and adaptation to adverse environments. By contrast, majority of these families that are merely present in a specific lineage or in a few closely related species have not been well functionally explored until recently. The fast-growing progresses being made in the actions of non-conserved miRNAs nowadays in diverse plant species may represent a highly promising research field in future. This review thereby summarizes the emerging advances in our understanding of the biogenesis, associated effectors, modes to targets, and biological functions of plant non-conserved miRNAs. In addition, it outlines the regulatory units recently discovered between conserved miRNAs and their alternative targets.

In flowering plants, proper development of stamens, the male reproductive organs, is required for successful sexual reproduction. In Arabidopsis thaliana normally six stamen primordia arise in the third whorl of floral organs and subsequently differentiate into stamen filaments and anthers, where male meiosis occurs, thus ending the early developmental phase. This early phase is followed by a late developmental phase, which consists of a rapid elongation of stamen filaments coordinated with anther dehiscence and pollen maturation, and terminates with mature pollen grain release at anthesis. Increasing evidence suggests that auxin transport is necessary for both early and late phases of stamen development. It has been shown that different members of PIN (PIN-FORMED) family are involved in the early phase, whereas members of both PIN and P-glycoproteins of the ABCB (PGP) transporter families are required during the late developmental phase. In this review we provide an overview of the increasing knowledge on auxin transporters involved in Arabidopsis stamen formation and development and we discuss their role and functional conservation across plant species.