News Update on Salt Stress Research: June – 2019
Regulation of ion homeostasis under salt stress
When underneath salt stress, plants maintain a high concentration of K+ and an occasional concentration of Na+ within the cytoplasm. they are doing this by regulation the expression and activity of K+ and Na+ transporters and of H+ pumps that generate the propulsion for transport. though salt-stress sensors stay elusive, a number of the treater sign elements are known. proof suggests that a supermolecule enzyme complicated consisting of the myristoylated Ca-binding supermolecule SOS3 and also the serine/threonine supermolecule enzyme SOS2 is activated by a salt-stress-elicited calcium signal. The supermolecule enzyme complicated then phosphorylates and activates numerous particle transporters, like the cell membrane Na+/H+ antiporter SOS1. [1]
Photosynthesis under drought and salt stress: regulation mechanisms from whole plant to cell
Background: Plants are typically subjected to periods of soil and part water deficits throughout their life cycle moreover as, in several areas of the world, to high soil salinity. Understanding however plants answer drought, salt and co-occurring stresses will play a significant role in stabilising crop performance below drought and saline conditions and within the protection of natural vegetation. chemical action, in conjunction with cell growth, is among the first processes to be full of water or salt stress. [2]
A novel cis-acting element in an Arabidopsis gene is involved in responsiveness to drought, low-temperature, or high-salt stress.
Two genes, rd29A and rd29B, that square measure closely situated on the dilleniid dicot genus order, square measure differentially elicited below conditions of dehydration, cold, high salt, or treatment with exogenous abscisic acid (ABA). It seems that rd29A has a minimum of 2 cis-acting components, one concerned within the ABA-associated response to dehydration and therefore the different elicited by changes in diffusion potential, which rd29B contains a minimum of one cis-acting component that’s concerned in ABA-responsive, slow induction. we tend to analyzed the rd29A promoter in each transgenic dilleniid dicot genus and tobacco and known a unique cis-acting, dehydration-responsive component (DRE) containing nine bp, TACCGACAT, that’s concerned within the initial speedy response of rd29A to conditions of dehydration or high salt. DRE is additionally concerned within the induction by cold however doesn’t perform within the ABA-responsive, slow expression of rd29A. Nuclear proteins that specifically bind to DRE were detected in dilleniid dicot genus plants below either high-salt or traditional conditions. completely different cis-acting components appear to perform within the ballroom dance induction of rd29A and within the slow induction of rd29B below conditions of dehydration, high salt, or cold. [3]
Gene Expression analysis associated with salt stress in a reciprocally crossed rice population
The rice landrace Horkuch, endemic to the southern saline coast of Asian nation, is understood to possess salt tolerance traits and may thus contribute to a high yielding recipient for breeding functions. during this study, we have a tendency to reciprocally crossed Horkuch with high yielding however salt sensitive IR29 to notice the complement of genes that were chargeable for conferring salt tolerance versus sensitivity at the spermatophyte organic process stage. we have a tendency to checked out tolerant and sensitive F3 families from individual F2 segregating plants and analyzed them for differential factor expressions victimization RNAseq. In general, we have a tendency to ascertained higher numbers of genes differentially expressed in leaves compared to root tissues. This enclosed each upregulation and downregulation of organic phenomenon across our experimental factors. organic phenomenon shrivelled in sensitive leaf when stress exposure wherever tolerant plants showed the alternative trend. In root, tolerant plants expression shrivelled at higher time points of stress exposure. we have a tendency to conjointly ascertained a robust maternal cytoplasmatic impact on organic phenomenon and this was most evident in roots wherever there was upregulation in useful enrichments associated with phosphorylation, lepton carriers, transporter and ion transmembrane activities. Stress teams (tolerant and sensitive) response in F3 families were distinctive in each cytoplasmatic backgrounds and concerned unambiguously upregulated genes in tolerant progenies together with membrane detector proteins, enzymes involved sign pathways, like those manufacturing trehalose and G-protein coupled receptor proteins, photosynthesis-related enzymes and cyst usage additionally as prolamin precursor proteins concerned in refolding of proteins. On the opposite hand, sensitivity was found to be related to differential upregulation of solely range of|some|many} oxidoreduction proteins and better number of cell death connected genes compared to the tolerant response. Overall, our extremely replicated experimental style was powerful and allowed the detection of comparatively delicate differential expression. Our future goal is to correlate these expression variations with QTLs during this population, which might facilitate determine the relative importance of specific genetic loci and supply an instantaneous avenue for combining higher levels of salt tolerance with higher agronomical traits in rice. [4]
UV-B Radiation Impacts on Growth, Bulb Yield and Antioxidants in Onion under Salt Stress
Ultraviolet radiation thought of one amongst the environmental stresses that wide disturb most of the physio-biochemical processes within the plant. However, previous studies referred that irradiation of plant tissues with a coffee dose of UV-B radiation stimulates adjustive mechanisms and providing higher protection to alternative stresses. during this approach, a pot experiment was set get into the open field throughout the 2 growing seasons of 2014/2015 and 2015/2016. Transplants of purple onion (Giza 20), six weeks previous, were exposed to UV-B (280-320 nm) for fifteen min, then grownup plants were irrigated with 3 concentrations of NaCl (0, fifty and a hundred mM) as a challenge. The impact of low dose of UV-B was evaluated by determination of vegetative growth characteristics, bulb yield/plant and a few organic chemistry changes related to UV-B elicited tolerance. In general, plants irrigated with fifty and a hundred millimeter of NaCl remarkably expressed a discount in plant growth, yield and chlorophyl and b. Flavonoids were considerably reduced beneath the best level of salinity. Results showed that plants grownup from UV-B treated transplants were less laid low with salt stress that was obvious in increasing plant contemporary weight, shoot height, range of leaves/plant, leaf length, leaf diameter and neck thickness. Moreover, actinic radiation treatment eased onion bulb yield in term of contemporary bulb weight, bulb length, bulb diameter and harvest index. the improved tolerance was noticed by increasing organic osmolytes (free amino acids, reducing sugars and total sugars) and elicited inhibitor system (total soluble phenols, carotenoids, flavonoids, oxidase (POD), polyphenol enzyme (PPO) and ascorbate oxidase (APX) in onion leaves and anthocyanin in bulbs. concerning supermolecule activity, thirty third of polymorphism was produced; negative markers were detected by actinic radiation + fifty millimeter NaCl and actinic radiation + a hundred millimeter NaCl. whereas one positive marker was detected by actinic radiation +100 millimeter NaCl at eighty seven.545 kDa that indicated that the interaction between salinity stress and UV-B radiation resulted in plant salt tolerance. [5]
Reference
[1] Zhu, J.K., 2003. Regulation of ion homeostasis under salt stress. Current opinion in plant biology, 6(5), pp.441-445. (Web Link)
[2] Chaves, M.M., Flexas, J. and Pinheiro, C., 2009. Photosynthesis under drought and salt stress: regulation mechanisms from whole plant to cell. Annals of botany, 103(4), pp.551-560. (Web Link)
[3] Yamaguchi-Shinozaki, K. and Shinozaki, K., 1994. A novel cis-acting element in an Arabidopsis gene is involved in responsiveness to drought, low-temperature, or high-salt stress. The Plant Cell, 6(2), pp.251-264. (Web Link)
[4] Gene Expression analysis associated with salt stress in a reciprocally crossed rice population
Samsad Razzaque, Sabrina M. Elias, Taslima Haque, Sudip Biswas, G. M. Nurnabi Azad Jewel, Sazzadur Rahman, Xiaoyu Weng, Abdelbagi M. Ismail, Harkamal Walia, Thomas E. Juenger & Zeba I. Seraj
Scientific Reportsvolume 9, Article number: 8249 (2019) (Web Link)
[5] M. R. Abdellatif, Y. and K. Al-Senosy, N. (2018) “UV-B Radiation Impacts on Growth, Bulb Yield and Antioxidants in Onion under Salt Stress”, International Journal of Plant & Soil Science, 24(2), pp. 1-14. doi: 10.9734/IJPSS/2018/43479. (Web Link)