Biochemistry and Plant Molecular Physiology

The experiment was conducted with 22 germplasm and laid out in randomized block design with three replications. The path revealed that days to 50% flowering, days maturity, plant height at harvest, No. of primary branches at harvest, No. of nodes at harvest, root nodules at 60 days, chlorophyll content (SPAD), days to picking 1, days to picking 2, No. of pods per plant, pods length (cm) pod yield (g/plant), shelling (%), pod length (cm), No. of primary branches at 40 days, number of seed, average pod weight (g), No. of seeds per pod had high positive direct effect on pod yield (q/ha) in all the environment under consideration, where as No. of leaves per plant at harvest, dry of 100 seed (g) and shelling (%) showed negative direct effect on pod yield (q/ha) in EI and EII of garden pea genotypes. The contribution of individual traits towards the total divergence was found maximum for pod yield q/ha, No. of leaves at 60 days, days to picking 2, pod length (cm), No. of seeds per pod and dry of 100 seed (g) in E-I and E-II. On the basis of D 2 values, 22 genotypes were grouped into 4 clusters. The cluster III showed maximum intra cluster D 2 value (D 2 = 23.20) followed by cluster I (D 2 = 20.56) and cluster II (D 2 = 19.97), whereas cluster IV showed zero value for intra cluster distance. The highest inter cluster divergence was observed between genotypes of cluster II and IV (70.57), followed by cluster III and cluster IV (57.66), cluster II and cluster III (55.19), cluster I and cluster II (52.44), cluster I and cluster III (36.85). The cluster distance was lowest between clusters I (20.56) and cluster IV (36.56).

Abstract Citrus exocortis is a grafting disease caused by Citrus Exocortis Viroid (CEVd). The knowledge of the viroid’s incidence and distribution are necessary to further apply control measures. The objective of this work was to apply the real time PCR assay for the detection of CEVd in samples collected from symptomatic CEVd-infected plants in Mitidja (North Algeria). The assay showed an excellent diagnostic specificity where 38 out of 50 samples showed a positive reaction for CEVd, which revealed the presence of CEVd in citrus orchards with a prevalence of 76%. Consequently, this work offers a quick alternative to conventional methods for the early diagnosis and the prevalence assessment of CEVd.

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The model legume Medicago truncatula possesses a single outward Shaker K+ channel, whereas Arabidopsis thaliana possesses two channels of this type, named AtSKOR and AtGORK, with AtSKOR having been shown to play a major role in K+ secretion into the xylem sap in the root vasculature and with AtGORK being shown to mediate the efflux of K+ across the guard cell membrane, leading to stomatal closure. Here we show that the expression pattern of the single M.truncatula outward Shaker channel, which has been named MtGORK, includes the root vasculature, guard cells and root hairs. As shown by patch-clamp experiments on root hair protoplasts, besides the Shaker-type slowly activating outwardly rectifying K+ conductance encoded by MtGORK, a second K+ -permeable conductance, displaying fast activation and weak rectification, can be expressed by M.truncatula. A knock-out (KO) mutation resulting in an absence of MtGORK activity is shown to weakly reduce K+ translocation to shoots, and only in plants engaged in rhizobial symbiosis, but to strongly affect the control of stomatal aperture and transpirational water loss. In legumes, the early electrical signaling pathway triggered by Nod-factor perception is known to comprise a short transient depolarization of the root hair plasma membrane. In the absence of the functional expression of MtGORK, the rate of the membrane repolarization is found to be decreased by a factor of approximately two. This defect was without any consequence on infection thread development and nodule production in plants grown in vitro, but a decrease in nodule production was observed in plants grown in soil.

In a grapevine segregating population, genomic regions governing berry pH were identified, paving the way for breeding new grapevine varieties best adapted to a warming climate. As a consequence of global warming, grapevine berry acidity is expected to dramatically decrease. Adapting grapevine (Vitis vinifera L.) varieties to the climatic conditions of the future requires a better understanding of the genetic architecture of acidity-related traits. For this purpose, we studied during five growing seasons 120 individuals from a grapevine biparental cross. Each offspring was genotyped by simple sequence repeats markers and by hybridization on a 20-K Grapevine Illumina® SNP chip. Quantitative trait loci (QTLs) for pH colocalized with QTLs for the ratio between potassium and tartaric acid concentrations, on chromosomes 10, 11 and 13. Strong QTLs for malic acid concentration or for the malic acid-to-tartaric acid ratio, on chromosomes 6 and 8, were not associated with variations of pH but can be useful for controlling pH stability under high temperatures. Our study highlights the interdependency between acidity parameters and consequently the constraints and degrees of freedom for designing grapevine genotypes better adapted to the expected warmer climatic conditions. In particular, it is possible to create grapevine genotypes with a high berry acidity as the result of both high tartaric acid concentrations and low K+ accumulation capacities.

Our study exploits time ‐ the relatively unexplored dimension of gene regulatory networks (GRNs) ‐ to learn the temporal transcriptional logic that underlies dynamic nitrogen (N) signaling in plants [1, 2]. Because causality moves forward in time, fine‐scale time‐series experiments are a valuable resource to infer GRN models that can predict TF‐target relationships in out‐of‐sample data ‐ the ultimate goal in systems biology [3]. First, using fine‐scale time‐series transcriptome datasets from N‐treated plants we developed a in a “just‐in‐time” analysis approach that uncovered a temporal cascade of cis‐regulatory elements underlying dynamic N‐signaling [2]. Next, to learn the associated transcription factor (TF) cascade, we inferred a GRN using a time‐based machine learning method ‐ Dynamic Factor Graph ‐ capable of predicting future gene responses under untested conditions [1]. We performed network validation studies using TF perturbations in plant cells using the TARGET system [4], and also in planta [2]. Our TF‐target validations of seven TF hubs in this predicted network were used in a precision/recall AUPR analysis to identify high‐confidence TF‐target edges in the time‐inferred GRN [1]. This high‐confidence GRN recovered TFs previously validated in the N‐response, as well as novel ones that were validated to regulate 15NO3−‐uptake and assimilation in planta [1]. This validated time‐based GRN now provides the temporal transcriptional logic and high‐confidence target predictions for >150 TFs in the dynamic N‐signaling response in Arabidopsis [1, 2]. More broadly, this time‐based approach ‐ can be applied to uncover the temporal transcriptional logic for any signaling response system in biology, agriculture or medicine.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Sensitive and rapid detection of organophosphate toxicants is highly relevant and important in environmental protection and food safety.

Sanguisorba minor Scop. is a perennial plant native to the Mediterranean region which exhibits several medicinal activities. In the present study, plant growth, chemical composition, and antitumor and antimicrobial properties of S. minor plants were evaluated under different growing conditions. In particular, plants were grown on different substrates, namely (A) peat, (B) peat : perlite (1 : 1) and (C) peat : perlite (2 : 1). The dry weight of the aerial parts and roots was higher for the peat treatment (A), whereas plant growth was severely affected in the peat : perlite (1 : 1) treatment (B). The major detected sugars were fructose and glucose, while the peat : perlite (2 : 1) treatment resulted in a significant increase of α-tocopherol, glucose and total sugars content, especially in the aerial parts. Oxalic acid and citric acid were the major organic acids detected, with a varied effect of growth substrate on organic acid profile. Growth substrate and plant part also had a significant effect on fatty acid composition, especially on linoleic acid and α-linolenic acid content which was higher in the peat : perlite (1 : 1) treatment in both aerial parts and roots. An impact on the composition of phenolic compounds was also observed, where the plants grown on peat : perlite (2 : 1) and peat : perlite (1 : 1) substrates had the highest content of individual and total phenolic compounds in their aerial parts and roots, respectively. Moreover, roots contained significantly higher amounts of phenolic compounds than the aerial parts. Moreover, plant extracts exhibited antiproliferative activity against four tumor cell lines (HeLa, HepG2, MCF-7 and NCI-H460) and a primary culture of porcine liver cells (PLP2), as well as significant antimicrobial properties. In conclusion, S. minor presented significant bioactive properties, while growth substrates affected the nutritional value, chemical composition, antitumor and antimicrobial properties of the species which could be probably attributed to the higher phenolic compound content and different compositions of phenolic compounds. Therefore, although the species is commonly found in the Mediterranean region, it is underexploited yet and its plant tissues could be a potential source of natural bioactive compounds with further use in pharmaceutical and medicinal applications.

La domestication des espèces forestières constitue un élément important dans le cadre du renforcement de la résilience des petits producteurs en milieu rural. La tolérance à la dessiccation des semences de Parinari curatellifolia, Vitex doniana et Zanthoxylum zanthoxyloides ont été étudiées et les méthodes directes et indirectes de classification des semences ont été utilisées. Aucune semence fraîche de l’ensemble des 3 espèces n’a germé quel que soit le stade de maturité des fruits considéré dans cette étude. Après séchage à 5% de teneur en eau, les semences de Vitex doniana et Zanthoxylum zanthoxyloides ont donné des pourcentages de germination très variables. Pour Vitex doniana, on a enregistré : 4% pour les semences des fruits verts ; 2% pour les semences des fruits intermédiaires et 36% pour les semences des fruits mûrs. Tandis que pour Zanthoxylum zanthoxyloides, les semences des fruits mûrs ont germé à 3%. Quant à Parinari curatellifolia, aucune semence après séchage. Cette mauvaise germination de ces espèces n’a pas permis de statuer sur la catégorie de leurs semences. Les isothermes d’absorption d’eau des semences révèlent qu’elles doivent être séchées à froid dans des milieux ayant une humidité relative comprise entre 10 et 14% pour Parinari curatellifolia et Vitex doniana, et entre 10 et 65% pour Zanthoxylum zanthoxyloides, pour atteindre la teneur de 5% pour la conservation à long terme.© 2017 International Formulae Group. All rights reserved.Keywords: Parinari curatellifolia, Vitex doniana, Zanthoxylum zanthoxyloides, tolerance à la dessicassion, Burkina FasoEnglish Title: Desiccation tolerance of Parinari curatellifolia planch. ex benth, Vitex doniana sweet and Zanthoxylum zanthoxyloides (lam) watermannEnglish AbstractTree domestication is a key element to strength food supply in the rural area in order to increase smallholder farmer’s resilience to climate change. Parinari curatellifolia, Vitex doniana and Zanthoxylum zanthoxyloides seeds tolerance to desiccation was studied using indirect and direct classification method of seed. None fresh seed was germinated whatever the maturity stage of fruit. Seed germination rate after drying at 5% moisture contain was 4% (green fruit), 2% (intermediate fruit) and 36% (mature fruit) for Vitex doniana, and 3% (mature fruit) for Zanthoxylum zanthoxyloides. None of Parinari curatellifolia seed had geminated at this drying stage. The lower germination of the seed did not allow to conclude on their category. The water sorption isotherms revealed that seeds must be dried under cold conditions at relative humidity between 10 and 14 % for Parinari curatellifolia and Vitex doniana and between 10 and 65% Zanthoxylum zanthoxyloides; to reach the maximum level condition at 5% moisture content for long term conservation.Keywords: Parinari curatellifolia, Vitex doniana, Zanthoxylum zanthoxyloides, desiccation tolerance, Burkina Faso