Majority legumes in the temperate and arctic zones have water-impermeable seeds (physical dormancy, PY). However, various authors have reported that seeds of some Caragana species are water-permeable and thus non-dormant. We (1) tested seeds of 15 species of Caragana matured in the same site in 2014, 2016 and/or 2017 for presence of PY, (2) determined if dry storage decreased or increased the percentage of seeds with PY and (3) located the site on the seed coat of 11 species where water enters the seed. Sixty-three percent and 45% of the seeds of C. roborovskyi had PY in 2016 and 2017, respectively, but only 0-14% of the seeds of the other 14 species had PY. The palisade layer in the seed coat of water impermeable seeds had no cracks in it, whereas cracks were present in the palisade layer of water-permeable seeds. Year of collection and dry storage had significant effects on imbibition of two species (C. acanthophylla and C. roborovskyi). In two (C. acanthophylla and C. roborovskyi) of the 11 species tested, the hilum was the site of water entry into seeds (control seeds, not any dormant broken treatments), but for the other nine species tested water entered through all parts of the seed coat.

In pursuit of developing fast and accurate species-level molecular identification methods, we tested six DNA barcodes, namely ITS2, matK, rbcLa, ITS2+matK, ITS2+rbcLa, matK+rbcLa and ITS2+matK+rbcLa, for their capacity to identify frequently consumed but geographically isolated medicinal species of Fabaceae and Poaceae indigenous to the desert of Cholistan. Data were analysed by BLASTn sequence similarity, pairwise sequence divergence in TAXONDNA, and phylogenetic (neighbour-joining and maximum-likelihood trees) methods. Comparison of six barcode regions showed that ITS2 has the highest number of variable sites (209/360) for tested Fabaceae and (106/365) Poaceae species, the highest species-level identification (40%) in BLASTn procedure, distinct DNA barcoding gap, 100% correct species identification in BM and BCM functions of TAXONDNA, and clear cladding pattern with high nodal support in phylogenetic trees in both families. ITS2+matK+rbcLa followed ITS2 in its species-level identification capacity. The study was concluded with advocating the DNA barcoding as an effective tool for species identification and ITS2 as the best barcode region in identifying medicinal species of Fabaceae and Poaceae. Current research has practical implementation potential in the fields of pharmaco-vigilance, trade of medicinal plants and biodiversity conservation.

The internal transcribed spacer (ITS) region is situated between 18S and 26S in a polycistronic rRNA precursor transcript. It had been proved to be the most commonly sequenced region across plant species to resolve phylogenetic relationships ranging from shallow to deep taxonomic levels. Despite several taxonomical revisions in Cassiinae, a stable phylogeny remains elusive at the molecular level, particularly concerning the delineation of species in the genera Cassia, Senna and Chamaecrista. This study addresses the comparative potential of ITS datasets (ITS1, ITS2 and concatenated) in resolving the underlying morphological disparity in the highly complex genera, to assess their discriminatory power as potential barcode candidates in Cassiinae.

Previous works resolved diverse phylogenetic positions for genera of the Fabaceae tribe Thermopsideae, without a thoroughly biogeography study. Based on sequence data from nuclear ITS and four cpDNA regions (matK, rbcL, trnH-psbA, trnL-trnF) mainly sourced from GenBank, the phylogeny of tribe Thermopsideae was inferred. Our analyses support the genera of Thermopsideae, with the exclusion of Pickeringia, being merged into a monophyletic Sophoreae. Genera of Sophoreae were assigned into the Thermopsoid clade and Sophoroid clade. Monophyly of Anagyris, Baptisia and Piptanthus were supported in the Thermopsoid clade. However, the genera Thermopsis and Sophora were resolved to be polyphyly, which require comprehensive taxonomic revisions. Interestingly, Ammopiptanthus, consisting of A. mongolicus and A. nanus, nested within the Sophoroid clade, with Salweenia as its sister. Ammopiptanthus and Salweenia have a disjunct distribution in the deserts of northwestern China and the Hengduan Mountains, respectively. Divergence age was estimated based on the ITS phylogenetic analysis. Emergence of the common ancestor of Ammopiptanthus and Salweenia, divergence between these two genera and the split of Ammopiptanthus species occurred at approximately 26.96 Ma, 4.74 Ma and 2.04 Ma, respectively, which may be in response to the second, third and fourth main uplifts of the Qinghai-Tibetan Plateau, respectively.

The current cultivation and plant breeding of Honeybush tea (produced from members of Cyclopia Vent.) do not consider the genetic diversity nor structuring of wild populations. Thus, wild populations may be at risk of genetic contamination if cultivated plants are grown in the same landscape. Here, we investigate the spatial distribution of genetic diversity within Cyclopia intermedia E. Mey.-this species is widespread and endemic in the Cape Floristic Region (CFR) and used in the production of Honeybush tea.

Cassia fistula (L.) (Fabaceae) is a medicinal plant from tropical Asia. It is known for its marked antioxidant activity, which is attributed to its high phenolic content. The present study aims at testing both the antioxidant and neuroprotective effects of a hydroalcoholic extract from the aerial parts of Cassia fistula using the Caenorhabditis elegans model, which is widely used in this context.

The evolutionary forces that gave rise to the exceptional plant species richness of the Cape Floristic Region (CFR) have also likely played a role at the intraspecific level (i.e. plant populations)-and thereby generating shared phylogeographic patterns among taxa. Here we test whether plant populations in the CFR exhibit phylogeographic breaks across the boundaries between Centres of Endemism (CoEs). The boundaries between CoEs (derived from the distribution ranges of endemic taxa and currently mapped at a coarse, Quarter Degree Square scale) represent a spatial proxy for the evolutionary diversifying drivers acting on plant taxa in the CFR.

Astragalus edulis (Fabaceae) is an endangered annual species from the western Mediterranean region that colonized the SE Iberian Peninsula, NE and SW Morocco, and the easternmost Macaronesian islands (Lanzarote and Fuerteventura). Although in Spain some conservation measures have been adopted, it is still necessary to develop an appropriate management plan to preserve genetic diversity across the entire distribution area of the species. Our main objective was to use population genetics as well as ecological and phylogeographic data to select Relevant Genetic Units for Conservation (RGUCs) as the first step in designing conservation plans for A. edulis. We identified six RGUCs for in situ conservation, based on estimations of population genetic structure and probabilities of loss of rare alleles. Additionally, further population parameters, i.e. occupation area, population size, vulnerability, legal status of the population areas, and the historical haplotype distribution, were considered in order to establish which populations deserve conservation priority. Three populations from the Iberian Peninsula, two from Morocco, and one from the Canary Islands represent the total genetic diversity of the species and the rarest allelic variation. Ex situ conservation is recommended to complement the preservation of A. edulis, given that effective in situ population protection is not feasible in all cases. The consideration of complementary phylogeographic and ecological data is useful for management efforts to preserve the evolutionary potential of the species.

The structure of the reproductive system of the sexual generation-males and oviparous females-of the pea aphid Acyrthosiphon pisum (Harris) (Hemiptera, Aphididae), a serious pest of cultivated plants of Fabaceae, was investigated. For the first time we describe the morphology, histology and ultrastructure of the reproductive system in both morphs of the sexual generation of aphids within one species, using light and fluorescent microscopy, as well as transmission and scanning electron microscopy. The results revealed that males have testes composed of three follicles fused by the upper ends of the vasa efferentia, the vasa deferentia run independently, the accessory glands are asymmetric and the ejaculatory duct shortened. Oviparous females have ovaries composed of seven ovarioles each. The lateral oviducts join to a short common oviduct connected with the unpaired spermatheca and paired accessory glands. Yolky eggs with an aggregation of symbiotic bacteria at the posterior pole are produced. Histologically, the components of genital tracts are broadly similar: the epithelial cells of the walls of the vasa deferentia and accessory glands of the male and oviparous female have secretory functions which correlate with the age of the studied morphs. We also found symbiotic bacteria within the vasa deferentia epithelial cells in males and within the cells of the lateral oviducts of females. Because the pea aphid is listed among the 14 species that are of the greatest economic importance, our results will be useful for managing aphid populations, protecting plants and ensuring global food security.

Photoperiodic flowering aligns plant reproduction to favourable seasons of the year to maximise successful production of seeds and grains. However understanding of this process in the temperate legumes of the Fabaceae family, which are important both agriculturally and ecologically, is incomplete. Previous work in the reference legume Medicago truncatula has shown that the FT-like gene MtFTa1 is a potent floral activator. While MtFTa1 is upregulated by long-day photoperiods (LD) and vernalisation, the molecular basis of this is unknown as functional homologues of key regulatory genes present in other species, notably CONSTANS in A. thaliana, have not been identified. In LD MtFTa1 maintains a near constant diurnal pattern of expression unlike its homologue FT in A. thaliana, which has a notable peak in expression at dusk. This suggests a different manner of regulation. Furthermore, M. truncatula possesses other FT-like genes such as two LD induced MtFTb genes which may also act in the regulation of flowering time. MtFTb genes have a diurnal pattern of expression with peaks at both four and sixteen hours after dawn. This study utilises RNA-Seq to analyse the transcriptome of M. truncatula leaves to identify genes which may regulate or be co-expressed with these FT-like genes following a shift from short-day photoperiods to inductive long-days. Specifically this study focuses on the first four hours of the day in the young leaves, which coincides with the first diurnal peak of the FTb genes. Following differential expression analysis at each timepoint, genes which alter their pattern of expression are distinguished from those which just alter their magnitude of expression (and those that do neither). It goes on to categorise these genes into groups with similar patterns of expression using c-means clustering and identifies a number of potential candidate photoperiod flowering time genes for future studies to consider.

Symbiotic bacteria, commonly called rhizobia, lead a saprophytic lifestyle in the soil and form nitrogen-fixing nodules on legume roots. During their lifecycle, rhizobia have to adapt to different conditions prevailing in the soils and within host plants. To survive under these conditions, rhizobia fine-tune the regulatory machinery to respond rapidly and adequately to environmental changes. Symbiotic bacteria play an essential role in the soil environment from both ecological and economical point of view, since these bacteria provide Fabaceae plants (legumes) with large amounts of accessible nitrogen as a result of symbiotic interactions (i.e., rhizobia present within the nodule reduce atmospheric dinitrogen (N2) to ammonia, which can be utilized by plants). Because of its restricted availability in the soil, nitrogen is one of the most limiting factors for plant growth. In spite of its high content in the atmosphere, plants are not able to assimilate it directly in the N2 form. During symbiosis, rhizobia infect host root and trigger the development of specific plant organ, the nodule. The aim of root nodule formation is to ensure a microaerobic environment, which is essential for proper activity of nitrogenase, i.e., a key enzyme facilitating N2 fixation. To adapt to various lifestyles and environmental stresses, rhizobia have developed several regulatory mechanisms, e.g., reversible phosphorylation. This key mechanism regulates many processes in both prokaryotic and eukaryotic cells. In microorganisms, signal transduction includes two-component systems (TCSs), which involve membrane sensor histidine kinases (HKs) and cognate DNA-binding response regulators (RRs). Furthermore, regulatory mechanisms based on phosphoenolopyruvate-dependent phosphotranspherase systems (PTSs), as well as alternative regulatory pathways controlled by Hanks-type serine/threonine kinases (STKs) and serine/threonine phosphatases (STPs) play an important role in regulation of many cellular processes in both free-living bacteria and during symbiosis with the host plant (e.g., growth and cell division, envelope biogenesis, biofilm formation, response to stress conditions, and regulation of metabolism). In this review, we summarize the current knowledge of phosphorylation systems in symbiotic nitrogen-fixing bacteria, and their role in the physiology of rhizobial cells and adaptation to various environmental conditions.