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Purpose. Juniper (Juniperus procera) is a common forest tree species in Saudi Arabia. The decline in many populations of J. procera in Saudi Arabia is mainly due to seed dormancy and loss of natural regeneration. This study assessed the effects of chemical and hormonal treatments on seed germination and seedling growth in juniper plants. Methods. The seeds were subjected to either chemical scarification with 90% sulfuric acid and 20% acetic acid for 6 min or hormonal treatment by seed soaking in two concentrations (50 and 100 ppm) of three growth regulators, namely, indole acetic acid (IAA), gibberellins (GA3), and kinetin, for 72 h. A control group without any seed treatment was also prepared. The experiments were performed in an incubator maintained at room temperature and under a light and dark period of 12 h for 6 w. The germinated seeds for each treatment were counted and removed from the dishes. The selected germinated seeds from different treatments were planted in a greenhouse and irrigated with tap water for another 6 weeks. The hormone-treated seedlings were sprayed with their corresponding hormone concentrations 1 w after planting. Results. The highest percentage of seed germination was significantly recorded after seed soaking in 50 ppm GA3, whereas treatment with IAA (100 ppm) resulted in the best seedling growth. Seedlings treated with the three phytohormones showed a significant increase in photosynthetic pigments, total soluble sugars, proteins, percentage of oil, IAA, GA3, and kinetin contents of juniper seedlings compared with the control value, whereas abscisic acid content was decreased compared with chemical treatments. Conclusion. The investigated different treatments had an effective role in breaking seed dormancy and improving seedling growth of J. procera, which is facing a notable decline in its population worldwide. Moreover, such an effect was more pronounced in the three phytohormones that succeeded in breaking dormancy and growth of the Juniperus plant than in the other treatments. [ABSTRACT FROM AUTHOR]

Purpose Juniper (Juniperus procera) is a common forest tree species in Saudi Arabia. The decline in many populations of J. procera in Saudi Arabia is mainly due to seed dormancy and loss of natural regeneration. This study assessed the effects of chemical and hormonal treatments on seed germination and seedling growth in juniper plants. Methods The seeds were subjected to either chemical scarification with 90% sulfuric acid and 20% acetic acid for 6 min or hormonal treatment by seed soaking in two concentrations (50 and 100 ppm) of three growth regulators, namely, indole acetic acid (IAA), gibberellins (GA3), and kinetin, for 72 h. A control group without any seed treatment was also prepared. The experiments were performed in an incubator maintained at room temperature and under a light and dark period of 12 h for 6 w. The germinated seeds for each treatment were counted and removed from the dishes. The selected germinated seeds from different treatments were planted in a greenhouse and irrigated with tap water for another 6 weeks. The hormone-treated seedlings were sprayed with their corresponding hormone concentrations 1 w after planting. Results The highest percentage of seed germination was significantly recorded after seed soaking in 50 ppm GA3, whereas treatment with IAA (100 ppm) resulted in the best seedling growth. Seedlings treated with the three phytohormones showed a significant increase in photosynthetic pigments, total soluble sugars, proteins, percentage of oil, IAA, GA3, and kinetin contents of juniper seedlings compared with the control value, whereas abscisic acid content was decreased compared with chemical treatments. Conclusion The investigated different treatments had an effective role in breaking seed dormancy and improving seedling growth of J. procera, which is facing a notable decline in its population worldwide. Moreover, such an effect was more pronounced in the three phytohormones that succeeded in breaking dormancy and growth of the Juniperus plant than in the other treatments.

Strains of the ascomycetous yeast Metschnikowia pulcherrima isolated from the internal tissues of fruits were evaluated for phytohormonal activity. IAA production in the culture liquid was determined by the chromatographic method (HPLC-UV). The production of the phytohormones zeatin and gibberellin (GA3) in the culture liquid was determined by a chromatographic method using a quadrupole time-of-flight mass spectrometry detector (Q- TOF LC / MS). IAA and zeatin were detected in the culture liquid of all strains studied. Synthesis of gibberellin (GA3) was detected in only 5 of 18 strains examined. On average, the strains showed the highest activity in the synthesis of IAA (6.668 µg/mL and 2.135 mg/g). Zeatin content was 3 orders of magnitude lower (0.365 ng/mL and 0.129 µg/g) and GA3 content was 4 orders of magnitude lower (0.076 ng/mL and 0.027 µg/g). According to our results, the yeast M. pulcherrima is not an active producer of zeatin and GA3 in amounts relevant to the plant. On the other hand, the average level of IAA synthesis detected in M. pulcherrima strains in this study is within the range of concentrations that can stimulate plant development and growth. Thus, endophytic strains of M. pulcherrima that produce plant-relevant levels of IAA could be improved to increase their synthesis ability and used as plant growth promoters in agricultural crops. [ABSTRACT FROM AUTHOR]

The ever-green avocado tree is of high economic importance. It was introduced to Yemen recently and there is a need to practice its sexual and vegetative propagation, as there is a limitation in the spread of its cultivation and the availability of agricultural seedlings resulting from sexual propagation. The research aims to study the effect of some chemical and physical treatments on the germination of avocado seeds and the growth characteristics of the resulting plants, in order to achieve the highest germination percentage and the best growth of plants. The research was conducted in the nurseries of the Organic Yemen Foundation, Sana’a - Yemen, and included a set of treatments: immersing seeds in different concentrations of gibberellin acid (GA3) (1000, 2000, 3000, 4000 parts per million (ppm)), and indole acetic acid (IAA) @1000ppm, naphthalene acetic acid (NAA) @1000ppm, hot water, and partial immersion of the seeds in tap water until germination begins, in addition to the control treatment (immersion in tap water). Some vegetative growth characteristics were studied (germination percentage, plant height (cm), number Leaves/plant) 60, 90, and 120 days after planting seeds. The research was implemented with a completely randomized design (CRD) in a single factor consisting of nine treatments (T1-T9). The results showed that the two seed soaking treatments in GA3 @1000 and @2000ppm recorded the highest germination percentage in both treatments after 60, 90, and 120 days of planting (73.33-100%) with a significant superiority over the control, the seed treatment with 1000ppm NAA, and the seed treatment with partial immersion in water. The lowest germination percentage recorded for the treatment of partial immersion of seeds in tap water, with a significant decrease (6.6-20%), as well as for the treatment of immersion of seeds in NAA @1000ppm (13.33- 46.66%). The highest plant height was generally recorded for seed soaking treatments in different concentrations of GA3 and other auxins and reached a peak (43.13 cm) using GA3 @4000ppm. The research showed the efficiency of plant growth regulators in accelerating the germination of avocado seeds by a high percentage as well as the growth of developing plants. [ABSTRACT FROM AUTHOR]

Phytohormones play a pivotal role in the growth and development of plants, including date palms. This study investigates the dynamics of four key hormones—indole-3-acetic acid (IAA), gibberellic acid (GA3), abscisic acid (ABA), and kinetin (Kin) across various developmental stages (pre-flowering, flowering, and fruiting) in three date palm phenotypes: phenotype derived from tissue culture and producing abnormal fruits (shees), phenotype derived from tissue culture and producing normal fruits (normal), and phenotype propagated by offshoots and producing normal fruits (vegetal). The results showed that IAA and GA3 levels in leaves exhibited a significant decline in the shees phenotype, while the normal and vegetal phenotypes displayed decreases from the pre-flowering to flowering stages, followed by increases in the fruiting stage. Interestingly, the vegetal phenotype showed a unique rise in IAA and GA3 levels during the fruiting stage. In flowers and fruits, the normal phenotype consistently exhibited the highest IAA and GA3 levels, while the shees phenotype displayed the lowest. Conversely, ABA levels showed distinct patterns among the phenotypes. The shees phenotype exhibited a sharp increase from pre-flowering to flowering, followed by a slight decrease in the fruiting stage. The normal phenotype displayed a significant decrease from pre-flowering to flowering, with a slight increase in the fruiting stage. The vegetal phenotype maintained relatively constant ABA levels. Kinetin levels displayed variations, with the normal phenotype consistently showing the highest concentrations. Leaves had the highest Kin levels during the pre-flowering stage, while fruits exhibited the lowest levels. [ABSTRACT FROM AUTHOR]

Abstract Background The mechanisms of abscisic acid (ABA) and auxin (IAA) in inducing adventitious root (AR) formation, biomass accumulation, and plant development under long-term waterlogging (LT-WL) conditions are largely unexplored. This study aimed to determine the roles of exogenous application of ABA and IAA in two woody plants (Cleistocalyx operculatus and Syzygium jambos) under LT-WL conditions. A pot experiment was conducted using a complete randomized design with two factors: (i) LT-WL and (ii) application of exogenous phytohormones (ABA and IAA) for 120 d. Results Results revealed that exogenous ABA and IAA promoted LT-WL tolerance in both species. In C. operculatus and S. jambos, plant height, the number of blades, leaf area, and fresh shoot weight were increased by exogenous IAA under LT-WL. However, exogenous ABA affected more the adventitious and primary root in C. operculatus compared to S. jambos. LT-WL decreased drastically the photosynthetic activities in both species, but adding moderate amounts of exogenous ABA or IAA protected the photosynthesis apparatus under LT-WL. Exogenous phytohormones at certain levels decreased the superoxide anion level and malondialdehyde accumulation in plants under LT-WL. Also, the increase of the peroxidases and superoxide dismutase activities by exogenous phytohormones was more marked in C. operculatus compared to S. jambos. Meanwhile, the catalase activity was down-regulated in both species by exogenous phytohormones. Exogenous ABA or IAA positively regulated the jasmonic acid content in ARs under LT-WL. Moderate application of exogenous ABA or IAA in plants under LT-WL decreased the ABA content in the leaves. Lower accumulation of IAA and ABA in the leaves of C. operculatus under LT-WL was positively correlated with a decrease in antioxidant activity. Conclusions Lastly, C. operculatus which has greater morphology indexes was more tolerant to waterlogging than S. jambos. Moreover, the adaptive strategies via exogenous ABA were more built around the below-ground biomass indexes particularly in C. operculatus, while exogenous IAA backed the above-ground biomass in both species. Overall, the exogenous hormones applied (spraying or watering) influenced differentially the plant’s responses to LT-WL. The phytohormonal profile of plants exposed to waterlogging stress varied depending on the species’ tolerance level.

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Plant growth-promoting rhizomicroflora inhabit the rhizosphere of plants, enhance plant growth with the release of metabolites and also inhibit soil-borne plant pathogens. In the present study, a total of sixty actinobacterial isolates were obtained from soil samples collected from the rhizosphere of cowpea and finger millet crop fields at the University of Agricultural Sciences, Bangalore. All the isolates were screened for their plant growth promoting activities viz, ammonia production, indole acetic acid (IAA), gibberellic acid (GA3 ) production, HCN production and phosphate solubilization. The results showed that the actinobacterial isolates differed in the levels of plant growth-promoting activities. Screening of the isolates for plant growth promoting traits, 26 isolates produced IAA and GA3, out of which the most active IAA and GA3 producers were UASBA46 and UASBA50, which produced 59.26 and 61.73 μgml-1 IAA, 24.28 and 25.31 μgml-1 GA3, respectively. UASBA46 (21.48%) and UASBA50 (22.63%) isolates showed the highest phosphate solubilization. Most of the actinobacterial isolates were positive for siderophore and ammonia production. UASBA46 and UASBA50 isolates produced the highest concentration of ACC-deaminase activity of 0.12 and 0.13mmol α-ketobutyrate mg-1 h-1, respectively. Further, these actinobacterial isolates were identified as Streptomyces antibioticus (UASBA50) and Streptomyces sp. (UASBA46) based on 16s rRNA partial genome sequencing. [ABSTRACT FROM AUTHOR]

Background: The mechanisms of abscisic acid (ABA) and auxin (IAA) in inducing adventitious root (AR) formation, biomass accumulation, and plant development under long-term waterlogging (LT-WL) conditions are largely unexplored. This study aimed to determine the roles of exogenous application of ABA and IAA in two woody plants (Cleistocalyx operculatus and Syzygium jambos) under LT-WL conditions. A pot experiment was conducted using a complete randomized design with two factors: (i) LT-WL and (ii) application of exogenous phytohormones (ABA and IAA) for 120 d. Results: Results revealed that exogenous ABA and IAA promoted LT-WL tolerance in both species. In C. operculatus and S. jambos, plant height, the number of blades, leaf area, and fresh shoot weight were increased by exogenous IAA under LT-WL. However, exogenous ABA affected more the adventitious and primary root in C. operculatus compared to S. jambos. LT-WL decreased drastically the photosynthetic activities in both species, but adding moderate amounts of exogenous ABA or IAA protected the photosynthesis apparatus under LT-WL. Exogenous phytohormones at certain levels decreased the superoxide anion level and malondialdehyde accumulation in plants under LT-WL. Also, the increase of the peroxidases and superoxide dismutase activities by exogenous phytohormones was more marked in C. operculatus compared to S. jambos. Meanwhile, the catalase activity was down-regulated in both species by exogenous phytohormones. Exogenous ABA or IAA positively regulated the jasmonic acid content in ARs under LT-WL. Moderate application of exogenous ABA or IAA in plants under LT-WL decreased the ABA content in the leaves. Lower accumulation of IAA and ABA in the leaves of C. operculatus under LT-WL was positively correlated with a decrease in antioxidant activity. Conclusions: Lastly, C. operculatus which has greater morphology indexes was more tolerant to waterlogging than S. jambos. Moreover, the adaptive strategies via exogenous ABA were more built around the below-ground biomass indexes particularly in C. operculatus, while exogenous IAA backed the above-ground biomass in both species. Overall, the exogenous hormones applied (spraying or watering) influenced differentially the plant’s responses to LT-WL. The phytohormonal profile of plants exposed to waterlogging stress varied depending on the species’ tolerance level. [ABSTRACT FROM AUTHOR]

This study was carried out in Tokat Gaziosmanpaşa University, Faculty of Agriculture, Field Crops Department, Industrial Plants Tissue Culture Laboratory in 2020. In the study, effects of different media (LS media, LS+1 mg/L Gibberellic acid (GA3), 0.1 mg/L kinetin (KIN) and LS+0.5 mg/L indole-3-acetic acid (IAA) on sweet potato genotypes (Havuc and Hatay Yerlisi) were investigated. Plant and root weights, plant and root lengths, and number of nodes and roots were determined. In this study, plants grown in cytokinin and gibberellin media had higher root number, root weight, root length, plant height, number of nodes and plant weight compared to the ones grown in auxin media. Havuc local genotype had higher values in terms of the investigated traits in all of the media studied.

Salvia miltiorrhiza is a medicinal plant that synthesises biologically-active tanshinones with numerous therapeutic properties. An important rate-limiting enzyme in the biosynthesis of their precursors is 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGR). This study presents the organ-specific expression profile of the S. miltiorrhiza HMGR4 gene and its sensitivity to potential regulators, viz. gibberellic acid (GA3), indole-3-acetic acid (IAA) and salicylic acid (SA). In addition, it demonstrates the importance of the HMGR4 gene, the hormone used, the plant organ, and the culture environment for the biosynthesis of tanshinones. HMGR4 overexpression was found to significantly boost the accumulation of dihydrotanshinone I (DHTI), cryptotanshinone (CT), tanshinone I (TI) and tanshinone IIA (TIIA) in roots by 0.44 to 5.39 mg/g dry weight (DW), as well as TIIA in stems and leaves. S. miltiorrhiza roots cultivated in soil demonstrated higher concentrations of the examined metabolites than those grown in vitro. GA3 caused a considerable increase in the quantity of CT (by 794.2 µg/g DW) and TIIA (by 88.1 µg/g DW) in roots. In turn, IAA significantly inhibited the biosynthesis of the studied tanshinones in root material. [ABSTRACT FROM AUTHOR]

Introduction Cowpea (Leguminosae: Papilionoidae) represents the main food legume and a versatile crop in tropical region. It is drought tolerant and could perform better growth in warm climates. It is most popular in the semi-arid regions of the tropics where other food legumes are available. This crop has been described as the major source of dietary protein in tropical and subtropical regions of the world especially where animal protein consumptions are low. Efforts made to maximize yield, is largely hampered by adverse effect of abiotic stress such as salinity and drought. These effects cause a huge loss due to low yield and failure of the crop to establish in some cases. Alternative approach towards efficient and cost effective means of production of cowpea in the tropical regions is very desirable. Pre-sowing hardening seed treatment is an easy, low cost and low risk technique and also an alternative approach recently used to overcome the effect of abiotic stresses in agricultural production. Increased germination rate and uniformity have been attributed to metabolic repair during imbibition, buildup of germination enhancing metabolites, osmotic adjustment, and, for seeds that are not redried after treatment, a simple reduction in imbibition lag time. The beneficial effects of priming have also been demonstrated for many field crops such as wheat, sugar beet, maize, soybean and sunflower. The main objective was to assess the physiological effect of Indole 3acetic acid (IAA) and gibberellic acid (GA3) on germination and seedling growth of cowpea. Material and Methods This experiment was carried out at the Seed Testing Laboratory, Department of Seed Science & Technology, at the Shoushtar University in Iran, with an objective to determine the rate of seed germination and seedling growth which influenced by various concentrations of growth regulators in cowpea (Vigna sinensis L.). Seeds of cowpea were obtained from the International Institute of Agriculture (IITA), Safiabad Research Station., Ahvaz, Iran. Before the start of experiment, seeds were surface sterilized in 1% sodium hypochlorite solution for 3 min, then rinsed with sterilized water and air-dried. Moisture content of seed was determined by using oven at 103 C for 12 hrs and was found 12% as recommended value. Different concentrations of the growth substances prepared in the laboratory were transferred from the reagent bottles into 50mls conical flasks which were clearly labelled according to the concentration of the growth substances to be used in the soaking treatment. The seeds were soaked in the various concentrations of 20, 40 and 60 ppm of GA3 and IAA with a separate control set. These were soaked for 6 or 12 hours in the above concentrations and only double distilled water for the control set. The seeds were sown on moist filter papers in 9cm well labelled petri dishes. Results and Discussion Emergence rate, root shoot lengths, seedling biomass are all important contributors of seed vigor. Higher emergence rate is the main foundation, which ensures an improvement of overall seedling performance. Seed germination rate varied significantly among the duration and hormone treatment (p < 0.05). The results showed significant increase in the rate of germination for seeds presoaked in the distilled water when compared with various hormones concentrations. Maximum increase of up to about 25 and 71% in compare to presoaked GA3 and IAA was observed. The soaking period of 12 hrs decreased the germination rate and uniformity emergence significantly in respect to 6 hrs treatment. Substantial variation on germination and other aspects were found between treatments. The seeds treated with GA3 showed better performance, in compare with IAA treatments. In comparison, concentrations of GA3 did not show any difference in respect of all measured traits which meant the higher concentration was as good as the lower concentration. Germination rate under the treatments of IAA at all concentrations recorded maximum by 12 hrs soaking. It was observed that for germination enhancement, distilled water was best suited, but in case of plumule length and uniformity emergence, did not show any significant effect with GA3. When the two hormones were compared, gibberellic acid (GA3) was observed more effective and responsive to the regulation of radicle and plumule elongation. Conclusion The findings of this study revealed that cowpea germination and early seedling growth were promoted by pre-sowing hardening treatments in distilled water. The lower concentration of hormones (20 ppm) was found to be more effective in inducing germination rate, total dry weight and uniformity emergence. Generally, treatment of water priming for 6 hours in the laboratory and in the field was the superior treatment in terms of the predominant criteria measured in bean; therefore, it is presented as the best combination of treatment in this study.

Vateria indica L. is an endemic arborescent recalcitrant tree species, native to the South-Western-Ghats of India. The natural regeneration process of the species is hindered by many factors including seed recalcitrance. Recently the species has been categorised as vulnerable since the population is fragmented and rapidly declining. Seed development is a highly complicated process which involves the interaction between phytohormones which regulate the process at different stages of morphogenesis. The orthodox seed development is marked by three distinct stages such as histodifferentiation, reserve accumulation and drying but in recalcitrant seeds, drying phase is absent. Recalcitrant seeds show marked differences from orthodox seeds in development. The onset of different stages is marked by a definite peaking and lowering of phytohormones and the hormonal pattern varies in orthodox and recalcitrant seeds. The present study was conducted to understand the interplay of phytohormones during embryogeny and the following natural embryo desiccation in the recalcitrant seeds of Vateria indica L. The present study revealed that the embryogeny and embryo drying in the recalcitrant seeds of Vateria indica L. shows a striking dissimilarity with the characteristic pattern of hormonal flux in orthodox seeds. [ABSTRACT FROM AUTHOR]

Soil pollution due to potentially toxic elements is a worldwide challenge for health and food security. Chelate-assisted phytoextraction along with the application of plant growth regulators (PGRs) could increase the phytoremediation efficiency of metal-contaminated soils. The present study was conducted to investigate the effect of different PGRs [Gibberellic acid (GA3) and indole acetic acid (IAA)] and synthetic chelator (EDTA) on growth parameters and Cd phytoextraction potential of Dysphania ambrosioides (L.) Mosyakin & Clemants grown under Cd-spiked soil. GA3 (10−7 M) and IAA (10−5 M) were applied four times with an interval of 10 days through a foliar spray, while EDTA (40 mg kg−1 soil) was once added to the soil. The results showed that Cd stress significantly decreased fresh biomass, dry biomass, total water contents, and photosynthetic pigments as compared to control. Application of PGRs significantly enhanced plant growth and Cd phytoextraction. The combined application of GA3 and IAA with EDTA significantly increased Cd accumulation (6.72 mg pot−1 dry biomass) and bioconcentration factor (15.21) as compared to C1 (Cd only). The same treatment significantly increased chlorophyll, proline, phenolic contents, and antioxidant activities (CAT, SOD, and POD) while MDA contents were reduced. In roots, Cd accumulation showed a statistically significant and positive correlation with proline, phenolics, fresh biomass, and dry biomass. Similarly, Cd accumulation showed a positive correlation with antioxidant enzyme activities in leaves. D. ambrosioides showed hyperaccumulation potential for Cd, based on bioconcentration factor (BCF) > 1. In conclusion, exogenous application of GA3 and IAA reduces Cd stress while EDTA application enhances Cd phytoextraction and ultimately the phytoremediation potential of D. ambrosioides. [ABSTRACT FROM AUTHOR]

Abstract Background Two field experiments were carried out in Researches and Production Station of National Research Centre, Al-Nubaria District, Al Behaira Governorate, Egypt. To study the effect of indole acetic acid (IAA) and /or gibberellic acid (GA3) on growth, photosynthetic pigments, yield, and chemical composition of mungbean seeds, different concentrations of IAA and/or GA3 were used. Results Results indicated that all treatments caused significant increases in morphological criteria, biochemical parameters, and yield of mungbean plants. IAA or GA3 with 50 mg/l concentration recorded the best values growth photosynthetic pigments, as well as, endogenous auxins, GA3, and cytokinins. Interaction of IAA 50 mg/l + GA3 50 mg/l gave the most effective treatment. The superiority of treatment IAA 50 mg/l, GA3 50 mg/l, and interaction of IAA 50 mg/l + GA3 50 mg/l recorded the same trend due to yield and yield components in characters’ plant height, pods no./plant, pods weight/plant, seeds no./pod, seed yield, straw yield, biological yield, total carbohydrates, protein in seeds (%), and N in seeds (%). Conclusion It could be concluded that foliar spray of 50 mg/l IAA + 50 mg/l GA3 was the most effective treatment on increasing growth and yield of mungbean.

The aim of this study was to obtain information about the content of endogenous hormones that causes flowers and fruit drop of wax apple. The variables observed in the six stages of flower and fruit development that drop easily and retention of indole-­3-­acetic acid (IAA), cytokinin (zeatin and kinetin), gibberellins (GA3), 1­-amino cyclopropane­-1-­carboxylic acid (ACC), total sugar, and starch. Six stages of development of wax apple fruit: (1) Bud Development (initial flowering) 0­-3 days before anthesis. (2) Anthesis (perfect blooming flowers), 0­-7 days after anthesis. (3) Fruit set, 7­-14 days after anthesis. (4) Fruit development, 14-­28 days after anthesis. (5) Fruit Maturation, 28­-35 days after anthesis. (6) Fruit ripening, 35­-50 days after anthesis. The results showed that the content of IAA, zeatin, GA3, and total sugar of flowers and fruit of wax apple at 6 stages that would fall smaller than those of retention and ACC content and starch was higher in flower and fruits that drop easily than retention. The kinetin content in the flower development that drop easily is smaller than the retention but in the fruit development the kinetin content is not significantly different between those that drop easily and retention.

The aim of this study was to obtain information about the content of endogenous hormones that causes flowers and fruit drop of wax apple. The variables observed in the six stages of flower and fruit development that drop easily and retention of indole3acetic acid (IAA), cytokinin (zeatin and kinetin), gibberellins (GA3), 1amino cyclopropane1carboxylic acid (ACC), total sugar, and starch. Six stages of development of wax apple fruit: (1) Bud Development (initial flowering) 03 days before anthesis. (2) Anthesis (perfect blooming flowers), 07 days after anthesis. (3) Fruit set, 714 days after anthesis. (4) Fruit development, 1428 days after anthesis. (5) Fruit Maturation, 2835 days after anthesis. (6) Fruit ripening, 3550 days after anthesis. The results showed that the content of IAA, zeatin, GA3, and total sugar of flowers and fruit of wax apple at 6 stages that would fall smaller than those of retention and ACC content and starch was higher in flower and fruits that drop easily than retention. The kinetin content in the flower development that drop easily is smaller than the retention but in the fruit development the kinetin content is not significantly different between those that drop easily and retention. [ABSTRACT FROM AUTHOR]

Background: Pea is the most important crop and vegetable in the world but it has low yield. There is a need to find the ways for the improvement of crop productivity. Plant growth regulators (PGRs) are extensively used in many crops for enhancement of yield and quality. This study was designed to find the influence of PGRs on growth, yield and quality of pea cultivars grown in Pakistan. Methods: Pot experiments were conducted to evaluate the effect of various plant growth regulators (IAA, NAA and GA3) on pea during 2018-19. Four cultivars of pea i.e. Meteor, Green cross, Sultan and Dollar were used in these experiments. There were 0, 100 and 200 mmolL-1 levels for each hormone that were applied as foliar spray after 14 days of germination. Experiment was laid down in completely randomized design (CRD) with three replicates. Result: Morphological, biochemical and yield attributes significantly increased in four cultivars of pea except variety Sultan for few parameters. Cultivar Meteor showed highly positive increasing effects on growth and yield attributes as compared to other treatments. Catalases (CAT) activities were increased and peroxidase dismutase (POD) activities were reduced. It can be concluded that reduction in POD activities helped to increase the defense mechanism of plants and high CAT activities caused better balance in plant metabolism as a result growth, yield and quality of pea were increased. All the variables including shoot length, shoot biomass, number of fruits, total seed yield, carbohydrates and protein had positive correlation with phytohormones. These outcomes might be good indicators to predict the best pea cultivars that can have positive promising response for growth, yield and quality traits under plant growth regulators (PGR). [ABSTRACT FROM AUTHOR]

Ber (Ziziphus maurtiana) is an important minor fruit crop of India. Over the years the crop is now widely domesticated and commercial orchards of Ber are now available. With wide commercialization, many physiological problems, i.e. flowers and fruit drop, embryo abortion, poor flowering and fruit setting, abnormal and small size fruits etc. were observed which cause huge loss to the growers. In order to minimize these problems, over the years many experiments and advancement have been done, and among them, usage of plant growth regulators is one of the most adopted methods and is utilized to improve flowering fruiting and yield with improved fruit quality. The current review discusses the role of different plant growth regulators and how they influence each fruit character. This information could be useful to the researchers in planning further advance research in this aspect and for the commercial growers to decide the proper treatments to mitigate the problems. [ABSTRACT FROM AUTHOR]

Indole-3-acetic acid (IAA) and gibberellic acid (GA3) are essential for the growth and development of plants. In the present study, the ameliorative potential of these phytohormones on growth, protein content, and antioxidant enzymes was investigated in in vitro-grown Solanum tuberosum L. cultivars 'Cardinal' and 'Desiree' under salt stress. A 4 × 3 factorial combination of 0, 40, 60, or 80 mM NaCl with 0, 7, or 14 μM IAA, or 0, 14, or 21 μM GA3, were added to Murashige and Skoog (MS) basal medium, followed by inoculation of nodal explants or callus cultures. The data for root and shoot number and length, number of nodes and leaves, fresh weight of plants, increase or decrease in fresh weight of callus cultures, total soluble protein, and superoxide dismutase (SOD) and peroxidase (POD) activities were recorded after 30 d. The growth of both callus cultures and nodal explants subjected to NaCl stress was substantially reduced compared with the control. Both IAA and GA3 successfully alleviated the harmful effects of salt stress on all of the growth parameters studied. Salt stress resulted in decreased protein content, which increased when the media also contained phytohormones. The activities of SOD and POD were increased with either IAA or GA3 under NaCl stress. Therefore, the exogenous application of both IAA and GA3 not only played a positive role in terms of in vitro potato growth but also significantly affected the biochemical parameters tested. [ABSTRACT FROM AUTHOR]

Background: Numerous cyanobacteria have the potential to reduce metallic ions to form pure metal nanoparticles in a green biosynthesis process. Aim: To investigate the production capacity of silver nanoparticles by the cyanobacterium Cyanothece sp. and to examine the effect of five different phytohormones, indole acetic acid, kinetin; gibberellic acid; abscisic acid; and methyl jasmonate, on this capacity. Methods: The cyanobacterial strain was grown for 60 days and the harvested cyanobacterium biomass was incubated with 0.1 mM of AgNO3. Percentage conversion of Ag+ to Ag0 was calculated to indicate the AgNPs’ production capacity. Different concentrations of the five phytohormones were added to cultures and the AgNP production was monitored throughout different time intervals. Results: Cyanothece sp. biosynthesized spherical AgNPs (diameter range 70 to 140 nm, average diameter 84.37 nm). The addition of indole acetic acid and kinetin provoked the maximum conversion (87.29% and 55.16%, respectively) of Ag+ to Ag0, exceeding or slightly below that of the control (56%). Gibberellic and abscisic acids failed to elevate the Ag+ to Ag0 conversion rate (45.23% and 47.95%, respectively) above that of the control. Methyl jasmonate increased the Ag+ to Ag0 conversion rate to 90.29%, although nearly all the cyanobacterial cultures died at the end. Conclusion: Phytohormones could be used to induce or inhibit the green production of AgNPs with the cyanobacterium Cyanothece sp. This novel manipulation technique may have several applications in agriculture or biomedicine.

Withania somnifera (L.) Dunal a member of the Solanaceae family, is a traditional medicinal plant commonly known in India as Ashwagandha. It is used for different diseases such as hiccup, cough, rheumatism, tuberculosis, and exhibits excellent antitumor and anti-bacterial activities as well. Direct organogenesis of plants using mature seeds provides faster response and is also a time saving approach, thus the present study was conducted to investigate the optimal concentrations and combinations of plant growth regulators with MS medium for the establishment of an efficient regeneration system in W. somnifera using mature seed as an explant. Therefore, an efficient in vitro protocol for high frequency regeneration has been developed using mature seeds as explant. In the present study, the multiple shoots along with embryogenic callus induction was best seen in MS medium supplemented with BAP (1.5 mg/L) and IAA (0.5 mg/L). Furthermore, MS medium fortified with GA3 (0.3 mg/L) and IBA (3.0 mg/L) alone was suited for shoot elongation and rhizogenesis respectively. The rooted plantlets were hardened and successfully established in the soil. The establishment of a highly reproducible regeneration system would greatly influence the efforts of improvement of the hereby studied medicinal plant species through useful gene transfer technology.

Withania somnifera (L.) Dunal a member of the Solanaceae family, is a traditional medicinal plant commonly known in India as Ashwagandha. It is used for different diseases such as hiccup, cough, rheumatism, tuberculosis, and exhibits excellent antitumor and anti-bacterial activities as well. Direct organogenesis of plants using mature seeds provides faster response and is also a time saving approach, thus the present study was conducted to investigate the optimal concentrations and combinations of plant growth regulators with MS medium for the establishment of an efficient regeneration system in W. somnifera using mature seed as an explant. Therefore, an efficient in vitro protocol for high frequency regeneration has been developed using mature seeds as explant. In the present study, the multiple shoots along with embryogenic callus induction was best seen in MS medium supplemented with BAP (1.5 mg/L) and IAA (0.5 mg/L). Furthermore, MS medium fortified with GA3 (0.3 mg/L) and IBA (3.0 mg/L) alone was suited for shoot elongation and rhizogenesis respectively. The rooted plantlets were hardened and successfully established in the soil. The establishment of a highly reproducible regeneration system would greatly influence the efforts of improvement of the hereby studied medicinal plant species through useful gene transfer technology. [ABSTRACT FROM AUTHOR]

The aim of this paper was to determine the changes in some biochemical and physiological processes, which occurred in seeds and seedlings of faba bean and to evaluate the germination dynamics and plant emergence after pre-sowing seeds treatment with a magnetic field. The study was carried out on Petri dishes in climatic chambers of the company HERAEUS (Germany). Each plate was lined with filter paper and 80 seeds of faba bean were sown. The paper was sprayed with the same amount of distilled water in each plate. Treatment of seeds significantly increased the activity of amylolytic enzymes in faba bean seeds and seedlings. The greatest differentiation in enzymatic activity between stimulated and nontreated seeds was noted after 96 h from the time of sowing. Seeds treated with the magnetic field showed greater dynamics of weight at the time of imbibition than nontreated seeds. Treating of seeds with a magnetic field considerably increased the amount of indole-3-acetic acid and gibberellic acid in germinating seeds, above-ground parts and in roots of faba bean seedlings. The pre-sowing treatment with a magnetic field had favorable effects on the growth and development of seedlings. [ABSTRACT FROM AUTHOR]

Investigations were made to identify, screen and characterize rice apoplastic fluid endophytic bacterial strains for osmotic stress tolerance and plant growth promoting activity. These bacterial strains were identified phylogentically as Bacillus subtilis TSAC5, Bacillus subtilis TSAA2, Bacillus sp. R2AA10, Bacillus cereus R2AA7, Bacillus marisflavi TSAC7, Cupriavidus alkaliphilus TSAC1, Delftia sp. TSAC2, Janibacter melonis R2AA1, Microbacterium oleivorans R2AA6, Kocuria rosea R2AA5, Pseudomonas aeruginosa NAAI3 and Sphingobium yanoikuyae R2AI1. Of these 12 strains, eight were obtained from drought tolerant rice varieties such as Anna R4 and IR DRT 64 and four from normal rice variety CO51. These endophytes exhibited varied level of osmotic stress tolerance created using different concentrations of PEG 6000 (-1.5, -3.0, -4.0, -4.5, -5.0 and -5.5 MPa) under in vitro conditions in liquid and solid medium. Among the 12 strains, Cupriavidus alkaliphilus TSAC1, Delftia sp. TSAC2, Bacillus marisflavi TSAC7, Janibacter melonis R2AA1, Kocuria rosea R2AA5, Pseudomonas aeruginosa NAAI3 and Sphingobium yanoikuyae R2AI1 showed moisture stress tolerance up to -5.5 MPa. Further increase in moisture stress of -6.0 MPa inhibited growth of 12 tested strains. These strains also exhibited Indole acetic acid (IAA), gibberellic acid (GA3) and extracellular polysaccharide (EPS) production and also showed ACC deaminase (ACCD) activity. Maximum extracellular proline production was found in Bacillus marisflavi TSAC7 under both normal and water stressed conditions. Higher IAA productivity was registered in Janibacter melonis R2AA1 followed by Cupriavidus alkaliphilus TSAC1 and Sphingobium yanoikuyae R2AI1 in the absence of PEG 6000. In the presence of PEG 6000 Delftia sp. TSAC2 recorded maximum IAA productivity. Bacillus subtilis TSAA2 showed greater ACC deaminase activity. EPS production was in the order of Pseudomonas aeruginosa NAAI3 followed by Sphingobium yanoikuyae R2AI1. Sphingobium yanoikuyae R2AI1 produced maximum quantity of GA3 both under normal and water stressed condition. None of the tested strains indicated insoluble phosphate, silicate and zinc solubilisation. [ABSTRACT FROM AUTHOR]

The objective of this study is to investigate the effect of different time and rates of boron (B) foliar application on olive (Olea europaea L.) tree's tissue boron concentration, total phenol, chlorophyll, total soluble sugars, and endogenous hormones. A field experiment was conducted during two successive seasons 2010/2011 and 2011/2012 using 20 years old olive trees cv. Frantoio. The trees are grown in sandy soil planted at 5 x 5 m apart under drip irrigation system at the Nuclear Research Center Experimental Farm, Inshas, El-Qaliubiya Governorate, Egypt. Boron was applied foliarly as boric acid at the following rates (0.0, 100, 200, 300, 400, 500 mg L-1) at flower initiation and after 1 and 2 months from flower initiation. Results showed that boron was significantly effective in increasing leaf, bud, and fruit boron concentration. Total phenol concentration in leaves and buds were significantly highest in the control treatment, significantly decreased as the boron application rate increased. Total chlorophyll, chlorophyll a and b, and total soluble sugars significantly increased as the boron application rate increased and the highest increase was achieved at 200 mg L-1 boron concentration rate. Leaf and bud endogenous indole acetic acid (IAA) and abscisic acid (ABA) were highest in the control treatment; they decreased as the boron application rate increased. However, gibberellic acid (GA3) increased in response to boron treatments compared with the control. The maximum increase was observed at 200 mg L-1 boron rate. We concluded that boron is mobile in olive tree as reproductive organs accumulated more boron than vegetative organs. There is evidence that boron is involved in reduction of phenols, increase in fruit set, and in sugar transport. A balance in endogenous hormones (IAA, GA, ABA) concentrations in olive tree has induced the maximum fruit set and yield. [ABSTRACT FROM AUTHOR]

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An experiment was conducted to investigate the effects of growth regulators on growth, yield and the quality of okra. Indole Acetic Acid (IAA) and Gibberellin (GA3) were applied as foliar spray and stem and flower injection at concentrations of 0, 30, 60, 90, and 120 mg/L on okra plants. The results showed that foliar spray of 90 mg/L IAA, increased the number of leaves, number of branches, number of flowers and number of pods. On the other hand, spraying of 90 mg/L GA3 increased stomatal conductance and pod weight of okra, while the highest chlorophyll content was recorded with 60 mg/L GA3. Stem injection of 120 mg/L IAA produced the highest number of leaves, number of branches, number of flowers, number of pods and plant height. Similarly, 120 mg/L GA3 as stem injection increased the number of branches, number of leaves, number of flowers and number of pods and total soluble solids (TSS). Flower injection of IAA at 30 and 90 mg/L increased pod size, pod weight, pod number and TSS content, while seed production was inhibited by 120 mg/L IAA. GA3 used in a 90 mg/L treatment as flower injection increased pod size and TSS content. It is concluded that the application of 120 mg/L IAA and 90 mg/L GA3 increased the growth, development and quality of the okra fruit and stem and that flower injection worked better than foliar spray. [ABSTRACT FROM AUTHOR]

Jatropha curcas (JC) is a crop with potential for use in biodiesel. Production of biodiesel requires plant seed as raw material, so the viability of JC for use in biodiesel will dependent greatly on the plant's production of flowers. Generally, this plant is monoecious, meaning it has both male and female flowers. However, very rarely JC plants may be andromonoecious. Andromonoecious specimens of JC produce hermaphrodite and male flowers in the same plant. The number of hermaphrodite flowers per inflorescence is generally low compared to the number of male flowers. The aim of this study was to increase the proportion of hermaphrodite flowers by using plant growth regulators (PGRs) in andromonoecious JC. Our experiment was conducted in Randomized Block Design (RBD) with 9 treatments, namely kinetin, GA3, and IAA with concentrations of 0 ppm as a control, 50 and 100 ppm of each PGRs. The treatments were applied to stem cuttings from each plant and repeated 4 times. PGRs were applied by spraying the leaves within the buds of each plant. Applications took place weekly beginning when the plants entered flower initiating phase, until inflorescence produced. Observations were conducted during the treatment period (10 weeks). Results showed that plants treated with IAA, GA3, and kinetin at 50 and 100 ppm produced increased inflorescence per plant. The increases measured were 155.4 and 92.9% of (IAA), 120.4 and 151% (GA3), 96.6 and 51.7% (kinetin) respectively. In addition, we found that application and GA3 at concentrations of 50 and 100 ppm, and kinetin at 50 ppm, increased the number of hermaphrodite flowers per inflorescence by 50%, and increased the number of hermaphrodite flowers per plant by 275.6 and 183.1% (IAA), 219.5 and 254.1% (GA3), 162.9 and 103.1% (kinetin) respectively. As would be expected, the number of fruit per plant increased in those specimens treated with IAA, GA3, and kinetin at 50 and 100 ppm. The increases measured were 301.7 and 167.4% (IAA), 211.7 and 257.0% (GA3), 162.5 and 101.4% (kinetin) respectively.

In concentrations ranging from 10-7 to 10-5 M IAA strongly stimulates the growth of the main axis and pleuridia internodal cells, while it does not affect the number of lateral branches and generative organs. In the higher concentrations it reduces the number of spermatozoids in the antheridium. In the same concentration range, GA3, inhibits the growth of the main axis and pleuridia internodal cells, does not affect the number of lateral branches, increases the number of antheridia and increases the number of forming spermatozoids. Incubation in mixture of both regulators has shown that: a) IAA eliminates the inhibitory effect of GA3 on the growth of internodal cells of the main axis and its stimulatory action is slightly weakened by GA3, b) IAA in a concentration of 10-5 M along with a low concentration of GA3, (10-7) increases the number of main axis lateral branches. The conclusion is drawn that the growth of the vegetative part of the thallus is more intense when auxin predominates, but generative development requires a high level of gibberellin.

In order to investigate the physical problem of flowering and fructification rate of endangered plant Camellia nitidissima, and provide the theory basis for species conservation, the contents and ratio of GA3, IAA, ZR and ABA in fruit branch leaves of C. nitidissima of more-flower, less-flower and non-flower were measured by ELISA(Enzyme-linked immunosorbent assay)method during blossom and fruit periods. In early-bloom stage, the content of IAA in leaves rised firstly and then fell, and its content of more-flower-plant was lower than that of less-flower-plant leaves; the content of ZR in flower-plant was higher than that of non-flower-plant; the content of GA3 appeared an upward trend, and its content of flower-plant was higher than non-flower-plant; the contents of ABA decreased firstly and then increased, and its content of more-flower-plant was lower than non-flower-plant. In full-bloom stage, the contents of IAA, GA3 and ABA declined overall; the content of ZR rised firstly and then fell; the contents of IAA, ZR, GA3 in more-flower plant were higher than those in less-flower-plant or non-flower-plant, while the content of ABA was less than that of other plants. During the bloom period, the ratio of IAA/ZR, IAA/ABA, ZR/ABA and GA3/ABA of flower-plant were higher than that of non-flower-plant, but the ratio of(IAA+GA3)/ZR was just in contrast, which also indicate the development of flower and fruit was related to not only single plant hormone but also the balance of plant hormones. During autumn shoot period with active vegetative growth, the ratio of IAA/ZR of non-flower-plant was larger than that of flower-plant, while the ratio of IAA/ZR of non-flower-plant was smaller in blossom and fruit period with vigorous reproductive growth, but the ratio of(IAA+GA3)/ZR was just in contrast. The results showed that high level of IAA, ABA, ZR and low level of GA3 in bud stage was benefitial for blossom, high content of IAA, ZR and low content of GA3, ABA in post-bloom stage was conducive to reducing blossom and fruit dropping, increased fruit-bearing rate and promoting fruit rapid growth, high ABA content before harvesting was favorable toward fruit ripening. Therefore, it can provide theoretical reference for using plant growth regulator to reduce the fallen petal and fruit abscission in production of C. nitidissima. [ABSTRACT FROM AUTHOR]

The experiment was conducted to determine the most effective PGRs for the optimum performance of chickpea cultivars and to select the most promising cultivar. The PGRs were IAA, GA, Kn, SA and Tria and the cultivars were DCP 92-3, GNG-469, KWR-108 and H1. Crop characters like shoot, root length, leaves number, number of pods per plant, 100-seed weight, seed yield and seed protein content were influenced by applied PGRs but most significantly with GA. The effect of spray of PGRs on seed protein content and also cultivar differences were found significant. Cultivar, DCP 92-3 gave the maximum seed yield which was 59.60% more over H 1, produced the lowest value and it was followed by KWR-108. Among the applied PGRs, GA produced the 174.48% higher seed yield than control, and this effect of GA was equalled by that of SA. The effect of interaction treatments was, found non-significant for seed yield. [ABSTRACT FROM AUTHOR]

The disti-icr of Kachchh contains many culturally important plants. However, their conservation status is little known due to direct and indirect htinsan activities. This snidywas undertaken with the aim of contributing to rheconservation of the native species of these semi-arid regions through germination trials under laboratory conditions. Mature fruits often selected species were collected randomly from the known habitats to obtain viable seeds. These seeds were pre-treated with growth regulators singly or in combination afrer acid scariflcarion or wirhoutscariijcation. Seeds were found to bedormant due to presence ofthickseed coat ordue to low level ofendogenous hormonal level. Most ofthescseeds required different storage. period to mature. Only seeds of Gspparis cartilaginea germinated without treatment while the other species required treatments. Addition ofgrowth regulators has enhanced seed germination in few taxa singly and in some plant cases in combination. [ABSTRACT FROM AUTHOR]

This research was carried out in order to determine the effects of nitrogen and phosphorus fertilization on yield, some fruit characteristics, hormone concentrations, and alternate bearing in pistachio (Pistacia vera L.) cv. 'Kirmizi' grafted on P. vera over 3 consecutive years. Nitrogen was applied at the rate of 0 (control), 800, 1000, and 1200 g tree-1, and phosphorus was applied at the rate of 0 (control), 200, 400, and 600 g tree-1 into the soil. As a result, although yield mostly decreased and nut weight increased, especially in the 2nd year ('off' year), considerable interactions among fertilizer rates were determined for only nut weight, auxin, gibberellic acid, and zeatin concentrations (P = 0.05). For all parameters investigated in this study, a stable and regular effect of fertilizers applied into the soil was not observed, probably because of this species' characteristics. Therefore, further research, including longer treatment periods, is needed to determine the effects of fertilizers. [ABSTRACT FROM AUTHOR]

Background: Numerous cyanobacteria have the potential to reduce metallic ions to form pure metal nanoparticles in a green biosynthesis process. Aim: To investigate the production capacity of silver nanoparticles by the cyanobacterium Cyanothece sp. and to examine the effect of five different phytohormones, indole acetic acid, kinetin; gibberellic acid; abscisic acid; and methyl jasmonate, on this capacity. Methods: The cyanobacterial strain was grown for 60 days and the harvested cyanobacterium biomass was incubated with 0.1 mM of AgNO3. Percentage conversion of Ag+ to Ag0 was calculated to indicate the AgNPs' production capacity. Different concentrations of the five phytohormones were added to cultures and the AgNP production was monitored throughout different time intervals. Results: Cyanothece sp. biosynthesized spherical AgNPs (diameter range 70 to 140 nm, average diameter 84.37 nm). The addition of indole acetic acid and kinetin provoked the maximum conversion (87.29% and 55.16%, respectively) of Ag+ to Ag0, exceeding or slightly below that of the control (56%). Gibberellic and abscisic acids failed to elevate the Ag+ to Ag0 conversion rate (45.23% and 47.95%, respectively) above that of the control. Methyl jasmonate increased the Ag+ to Ag0 conversion rate to 90.29%, although nearly all the cyanobacterial cultures died at the end. Conclusion: Phytohormones could be used to induce or inhibit the green production of AgNPs with the cyanobacterium Cyanothece sp. This novel manipulation technique may have several applications in agriculture or biomedicine. [ABSTRACT FROM AUTHOR]

Abstract: The effect of plant growth regulators and spear bud scales on spear elongation in asparagus was investigated. Spears of uniform size were immersed completely in indole-3-acetic acid (IAA), abscisic acid (ABA), gibberellic acid (GA3) or N 1-(2-chloro-4-pyridyl)-N 3-phenylurea (CPPU) in test tubes. IAA and GA3 slightly stimulated, and ABA inhibited, elongation of specific regions of the shoot, but overall the effects on total spear elongation were small. In contrast the cytokinin-active compound, CPPU, significantly increased spear length. Increasing CPPU concentration from 0 to 10ppm increased the elongation rate of spears. CPPU may influence spear length by stimulating the biosynthesis of native cytokinins or other plant growth promoter hormones as the naturally occurring cytokinin, zeatin riboside, was also found to stimulate spear elongation. In particular, CPPU greatly stimulated the growth of the first and second segments below the spear tip, and removal of spear bud scales inhibited this growth. CPPU did not reverse the growth suppression caused by removing spear bud scales suggesting that other factors may interact with cytokinins in promoting elongation. [Copyright &y& Elsevier]