Role of the durum wheat dehydrin in the function of proteases conferring salinity tolerance in Arabidopsis thaliana transgenic lines

Genetic Aspects and Molecular Causes of Seed Longevity in Plants-A Review

Seed longevity is the most important trait related to the management of gene banks because it governs the regeneration cycle of seeds. Thus, seed longevity is a quantitative trait. Prior to the discovery of molecular markers, classical genetic studies have been performed to identify the genetic determinants of this trait. Post-2000 saw the use of DNA-based molecular markers and modern biotechnological tools, including RNA sequence (RNA-seq) analysis, to understand the genetic factors determining seed longevity. This review summarizes the most important and relevant genetic studies performed in Arabidopsis (24 reports), rice (25 reports), barley (4 reports), wheat (9 reports), maize (8 reports), soybean (10 reports), tobacco (2 reports), lettuce (1 report) and tomato (3 reports), in chronological order, after discussing some classical studies. The major genes identified and their probable roles, where available, are debated in each case. We conclude by providing information about many different collections of various crops available worldwide for advanced research on seed longevity. Finally, the use of new emerging technologies, including RNA-seq, in seed longevity research is emphasized by providing relevant examples.

Review: Proteomic Techniques for the Development of Flood-Tolerant Soybean

Soybean, which is rich in protein and oil as well as phytochemicals, is cultivated in several climatic zones. However, its growth is markedly decreased by flooding stress, which is caused by climate change. Proteomic techniques were used for understanding the flood-response and -tolerant mechanisms in soybean. Subcellular proteomics has potential to elucidate localized cellular responses and investigate communications among subcellular components during plant growth and under stress stimuli. Furthermore, post-translational modifications play important roles in stress response and tolerance to flooding stress. Although many flood-response mechanisms have been reported, flood-tolerant mechanisms have not been fully clarified for soybean because of limitations in germplasm with flooding tolerance. This review provides an update on current biochemical and molecular networks involved in soybean tolerance against flooding stress, as well as recent developments in the area of functional genomics in terms of developing flood-tolerant soybeans. This work will expedite marker-assisted genetic enhancement studies in crops for developing high-yielding stress-tolerant lines or varieties under abiotic stress.

Diffusions of sound frequencies designed to target dehydrins induce hydric stress tolerance in Pisum sativum seedings

Among plant responses to environmentally induced stress modulating protein expression appears to be a key stage in inducible signaling. Our study was focused on an innovative strategy to stimulate plant stress resistance, namely, the use of targeted sequences of specific sound frequencies. The influence of acoustic stimulation on plant protein synthesis was investigated. In our study green peas, Pisum sativum, were cultured under hydric stress conditions with targeted acoustic stimulation. Acoustic sequences targeting dehydrins (DHN) which accumulate in plants in response to dehydration were studied. We experimented on pea seeding with two different sequences of sounds: the first one corresponded to DHN cognate protein and the second one was aimed at the DHN consensus sequence. Shoot elongation after pea seed germination was estimated by fresh weight gain studied in the presence of various conditions of exposure to both sequences of sounds. DHN expression in peas was quantified via ELISA tests and Western-blotting by using specific antibodies. A significant increase in fresh weight in peas grown under exposure to the DHN cognate sound sequence was observed, whereas the consensus sound sequence had no effect on growth. Moreover, the 37kDa DHN amount was increased in peas treated with the consensus acoustic sequence. These results suggest that the expression of DHN could be specifically modulated by a designed acoustic stimulus.

Heterologous Expression of Three Ammopiptanthus mongolicus Dehydrin Genes Confers Abiotic Stress Tolerance in Arabidopsis thaliana

Ammopiptanthus mongolicus, a xerophyte plant that belongs to the family Leguminosae, adapts to extremely arid, hot, and cold environments, making it an excellent woody plant to study the molecular mechanisms underlying abiotic stress tolerance. Three dehydrin genes, AmDHN132, AmDHN154, and AmDHN200 were cloned from abiotic stress treated A. mongolicus seedlings. Cytomembrane-located AmDHN200, nucleus-located AmDHN154, and cytoplasm and nucleus-located AmDHN132 were characterized by constitutive overexpression of their genes in Arabidopsis thaliana. Overexpression of AmDHN132, AmDHN154, and AmDHN200 in transgenic Arabidopsis improved salt, osmotic, and cold tolerances, with AmDHN132 having the largest effect, whereas the growth of transformed plants is not negatively affected. These results indicate that AmDHNs contribute to the abiotic stress tolerance of A. mongolicus and that AmDHN genes function differently in response to abiotic stresses. Furthermore, they have the potential to be used in the genetic engineering of stress tolerance in higher plants.

Causal Enzymology and Physiological Aspects May Be Accountable to Membrane Integrity in Response to Salt Stress in Arabidopsis thaliana Lines

Apart from their significance in the protection against stress conditions, the plant cell membranes are essential for proper development of the diverse surface structures formed on aerial plant organs. In addition, we signal that membrane remodeling and integrity are function of some of causal physiological and enzymological aspects such as the MDA, the ion leakage and also the monitoring of some phytozymes involved in lipid and cellulose metabolisms. Those last ones are related to the membrane structure (lipases and cellulases), that were assessed in durum wheat dehydrin transgenic context (YS, K₁-K₂, DH2, and DH4), proline metabolic mutant (P5CS_1-4) per comparison with the wild-type plant (Wt). We report also the docking data reinforcing the fact that the membrane integrity seems to be function of causal enzymological behaviors, through the molecular dynamic investigation resulting from the dehydrin-phytozyme interactions and also from the inhibition effect of the durum wheat LTP4 on the lipase activity.

Water regime and osmotic adjustment under warming conditions on wheat in the Yaqui Valley, Mexico

An experiment was carried out to evaluate the effect of increased temperature on roots and leaf water and osmotic potential, osmotic adjustment (OA) and transpiration on Triticum durum L. (CIRNO C2008 variety) during growth (seedling growth), tillering and heading phenophases. Wheat was sown under field conditions at the Experimental Technology Transfer Center (CETT-910), as a representative wheat crop area from the Yaqui Valley, Sonora México. Thermal radiators were placed at 1.20 m from the crop canopy. Treatments included warmed plots (2 °C) and ambient canopy temperature with five replicates. Temperature treatment was controlled using a (proportional, integrative, derivative) feedback control system on plots covering a circular area of r = 1.5 m. Results indicated a significant decrease in the osmotic potential of roots and leaves for the warmed plots. Water potential, under warming treatment, also experienced a significant reduction and a potential gradient was observed in both, roots and leaves, while the phenophases were delayed. Such results demonstrate that, under warmer conditions, plants increase water absorption for cooling. Hence, transpiration experienced a significant increase under warming in all phenophases that was related to the low root and leaf water potential. CIRNO C2008 also experienced OA in all phenophases with glycine betaine as the osmolyte with major contribution.

Structural and Functional Dynamics of Dehydrins: A Plant Protector Protein under Abiotic Stress

Abiotic stress affects the growth and development of crops tremendously, worldwide. To avoid adverse environmental effects, plants have evolved various efficient mechanisms to respond and adapt to harsh environmental factors. Stress conditions are associated with coordinated changes in gene expressions at a transcriptional level. Dehydrins have been extensively studied as protectors in plant cells, owing to their vital roles in sustaining the integrity of membranes and lactate dehydrogenase (LDH). Dehydrins are highly hydrophilic and thermostable intrinsically disordered proteins (IDPs), with at least one Lys-rich K-segment. Many dehydrins are induced by multiple stress factors, such as drought, salt, extreme temperatures, etc. This article reviews the role of dehydrins under abiotic stress, regulatory networks of dehydrin genes, and the physiological functions of dehydrins. Advances in our understanding of dehydrin structures, gene regulation and their close relationships with abiotic stresses demonstrates their remarkable ability to enhance stress tolerance in plants.