Search

Aleksandar Mikić was born in Pančevo, Serbia, on 9 January 1974, and died on 5 September 2021, Novi Sad, Serbia. He received BSc in 1998, MSc in 2008, and PhD in 2014 in Plant Genetics and Breeding at the University of Novi Sad, Faculty of Agriculture. He worked as Research Associate and annual legume breeder at the Institute of Field and Vegetable Crops in Novi Sad, Serbia, from 2000 to 2018. His fields of interest encompassed conventional and molecular genetics, genetic resources, breeding, agronomy, agroecology, and crop history of annual legumes. Dr. Mikić co-authored more than 350 journal papers, about 120 international conference papers, over 10 book chapters and one book. He has also authored more than 30 cultivars of annual legumes and various forage crops registered in Serbia and abroad. Aleksandar's scientific horizons were endless, including archaeobotany, linguistics, plant biology, breeding, and farmers communities.

The two lectures Gregor Mendel gave in the spring of 1865 to the Natural Science Society in Brno can be considered the ultimate origin of genetics. Here we reconstruct these lectures and their settings using digitized historical newspapers, and we compare these to Mendel's 1866-paper "Experiments on plant hybrids". The newspapers explained to their readers that Mendel used the term "Hybriden" in the sense of "Bastarden". Naturalists commonly used the latter term to describe hybrids between species in nature. Mendel's use of "Hybriden" and the avoidance of "Bastarden" in the 1866-paper and early letters to Nägeli regarding Pisum are particular. In English translations, both German words are translated as "hybrids" so that Mendel's differentiated use of words is no longer noticeable. We argue that with the use of "Hybriden" Mendel did not need to take a position on whether the Pisum parental forms were species or varieties, as Mendel considered these as extremes of a continuum. That Mendel probably started his pea crossings as a breeder may also have played a role; "Hybriden" was commonly used in horticulture. Mendel's use of "Hybriden" was unusual for the naturalists in the Natural Science Society, and newspaper reports indicate that this led to confusion. According to the Brünner Zeitung, legumes were not suitable for studies on hybridisation because such interspecific hybrids were rare in nature. However, in his 1866-article, Mendel explained that the garden pea was highly suitable for experimental hybridization due to its flower structure. In the Concluding Remarks of the 1866-article, Mendel showed that his findings were relevant for hybrids between wild species by reviewing the work of Gärtner and Kölreuter. We conclude that it is probable that this section was not part of the lectures and was added later to the paper to accommodate points raised in the discussion after the lectures.

Pea (Pisum sativum) is one of relatively few genetically amenable plant species with compound leaves. Pea leaves have a variety of specialized organs: leaflets, tendrils, pulvini and stipules, which enable the identification of mutations that transform or affect distinct parts of the leaf. Characterization of these mutations offers insights into the development and evolution of novel leaf traits. The previously characterized morphological gene Cochleata, conferring stipule identity, was known to interact with Stipules reduced (St), which conditions stipule size in pea, but the St gene remained unknown. Here we analysed Fast Neutron irradiated pea mutants by restriction site associated DNA sequencing. We identified St as a gene encoding a C2H2 zinc finger transcription factor that is regulated by Cochleata. St regulates both cell division and cell expansion in the stipule. Our approach shows how systematic genome-wide screens can be used successfully for the analysis of traits in species for which whole genome sequences are not available.

Pea (Pisum sativum L.) was the original model organism used in Mendel’s discovery (1866) of the laws of inheritance, making it the foundation of modern plant genetics. However, subsequent progress in pea genomics has lagged behind many other plant species. Although the size and repetitive nature of the pea genome has so far restricted its sequencing, comprehensive genomic and post genomic resources already exist. These include BAC libraries, several types of molecular marker sets, both transcriptome and proteome datasets and mutant populations for reverse genetics. The availability of the full genome sequences of three legume species has offered significant opportunities for genome wide comparison revealing synteny and co-linearity to pea. A combination of a candidate gene and colinearity approach has successfully led to the identification of genes underlying agronomically important traits including virus resistances and plant architecture. Some of this knowledge has already been applied to marker assisted selection (MAS) programs, increasing precision and shortening the breeding cycle. Yet, complete translation of marker discovery to pea breeding is still to be achieved. Molecular analysis of pea collections has shown that although substantial variation is present within the cultivated genepool, wild material offers the possibility to incorporate novel traits that may have been inadvertently eliminated. Association mapping analysis of diverse pea germplasm promises to identify genetic variation related to desirable agronomic traits, which are historically difficult to breed for in a traditional manner. The availability of high throughput ‘omics’ methodologies offers great promise for the development of novel, highly accurate selective breeding tools for improved pea genotypes that are sustainable under current and future climates and farming systems.

Mendel's paper 'Versuche über Pflanzen-Hybriden' is the best known in a series of studies published in the late 18th and 19th centuries that built our understanding of the mechanism of inheritance. Mendel investigated the segregation of seven gene characters of pea (Pisum sativum), of which four have been identified. Here, we review what is known about the molecular nature of these genes, which encode enzymes (R and Le), a biochemical regulator (I) and a transcription factor (A). The mutations are: a transposon insertion (r), an amino acid insertion (i), a splice variant (a) and a missense mutation (le-1). The nature of the three remaining uncharacterized characters (green versus yellow pods, inflated versus constricted pods, and axial versus terminal flowers) is discussed.

Pea (Pisum sativum L.) has a compound leaf like many other legume species. The 'semi-leafless' pea (afaf tltl), with all leaflets transformed into tendrils, is considered one of the most important achievements in pea breeding, due to a significantly enhanced standing ability and equally efficient dry matter production in comparison to normal-leafed genotypes (AFAF TLTL). 'Semi-leafless' cultivars provide high and stable grain yield and are dominant in the modern dry pea production worldwide. There are also 'semi-leafless' cultivars that are autumn-sown and those for forage production. The genotypes with all tendrils transformed into leaflets (afaf tltl), called 'acacia' or 'tendril-less', are extremely prone to lodging and may have importance in breeding for forage production. Little is known about the potential agronomic value of 'acacia-tendril-less' (afaf tltl) genotypes.

Background The genetic regulation of flower color has been widely studied, notably as a character used by Mendel and his predecessors in the study of inheritance in pea. Methodology/Principal Findings We used the genome sequence of model legumes, together with their known synteny to the pea genome to identify candidate genes for the A and A2 loci in pea. We then used a combination of genetic mapping, fast neutron mutant analysis, allelic diversity, transcript quantification and transient expression complementation studies to confirm the identity of the candidates. Conclusions/Significance We have identified the pea genes A and A2. A is the factor determining anthocyanin pigmentation in pea that was used by Gregor Mendel 150 years ago in his study of inheritance. The A gene encodes a bHLH transcription factor. The white flowered mutant allele most likely used by Mendel is a simple G to A transition in a splice donor site that leads to a mis-spliced mRNA with a premature stop codon, and we have identified a second rare mutant allele. The A2 gene encodes a WD40 protein that is part of an evolutionarily conserved regulatory complex.

Boron-containing organometallics are unique for the variety of ways in which they can be synthesized, the relatively mild conditions under which they cross-couple, their atom economy, ease of handling, and low environmental impact. Recently, organotrifluoroborates have proven to be highly useful and robust surrogates of boronic acids and boronate esters in a number of frequently utilized chemical transformations. One of the most highly utilized reactions for the formation of C-C bonds is the metal-halogen exchange reaction. However, the strong nucleophilicity and basicity of the metallating reagents precludes their use in the presence of tricoordinate organoboron reagents. We found that tetracoordinate potassium organotrifluoroborate salts could be used to circumvent this well-recognized problem.* The production of stereodefined alkenyl organometallics is a goal of ever-increasing value owing to the ability of these organometallics to cross-couple with little if any erosion in stereochemical purity. Access to cis -alkenylboron derivatives is well precedented in the literature, but the vast majority of examples possess a conspicuous dearth of functional groups. As part of a growing program to create highly functionalized potassium organotrifluoroborates and apply them in the context of natural product synthesis, we developed a facile method for the stereospecific production of cis-alkenylboron compounds.* Despite considerable development in the chemistry of acyl silanes and acylstannanes, the acylboron moiety has remained a mere curiosity until now. As “ate” complexes, acyltrifluoroborates lack the empty p orbital that lends to tricoordinate organoborons their high reactivity. These compounds are white, crystalline solids that display indefinite benchtop stability. Ab initio modeling has provided insight into many of the unique modes of reactivity that these unusual compounds possess.* *Please refer to dissertation for diagrams.

A high throughput proton nuclear magnetic resonance spectroscopy method for the metabolite fingerprinting of plants was applied to genetically modified peas (Pisum sativum) to determine whether biochemical changes, so called 'unintended effects', beyond those intended by incorporation of a transgene, were detectable. Multivariate analysis of 1H NMR (nuclear magnetic resonance) spectra obtained from uniformly grown glasshouse plants revealed differences between the transgenic and control group that exceeded the natural variation of the plants. When a larger data set of six related transgenic lines was analysed, including a null segregant in addition to the wild-type control, multivariate analysis showed that the distribution of metabolites in the transgenics was different from that of the null segregant. However, the profile obtained from the wild-type material was diverse in comparison with both the transgenics and the null segregant, suggesting that the primary cause of the observed differences was that the transformation process selects for a subset of individuals able to undergo the transformation and selection procedures, and that their descendants have a restricted variation in metabolite profile, rather than that the presence of the transgene itself generates these differences.