Anpassung von Nutzpflanzen an abiotischen Stress mithilfe von aktinvermittelter, stressresponsiver Membranstabilisierung
Zusammenfassung der Projektergebnisse
Abiotic stresses limit plant species' genetic potential and productivity. Abiotic stress tolerance is becoming more important in crop improvement strategies as climate change and human-caused environmental degradation threaten food security. Additionally, advanced biotechnological methods must be used to create new crop varieties that can better withstand environmental stresses to speed up crop improvement programmes. This and breeding practices are essential for food security. Wheat is a major cereal crop for one-third of the world. Drought and salinity, especially when combined with heat, greatly impact its productivity and quality. Drought stress increased Hsp70 gene expression in Erianthus arundinaceus, a wild sugarcane relative, according to our previous study. Expression also increased proportionally with drought stress intensity. The expression of Hsp70 was positively correlated with drought tolerance in E.arundinaceus. We isolated the Hsp70 gene from E. arundinaceus and introduced it into sugarcane, increasing cortical actin accumulation. This develops interlocking marginal lobes (IML) and helps sugarcane withstand abiotic stress by stabilising cell membranes. The Hsp70 orthologue from a drought-tolerant E. arundinaceus under the control of a drought-responsive ubiquitin promoter (Ubi 2.3) from Porteresia coarctata increased sugarcane Hsp70 expression by almost 2000 times. Wheat's importance and the challenges of improving crop quality by developing a plant species' ability to withstand multiple stress factors drove this project. We first assessed seven durum wheat varieties' physiological and molecular characteristics, including gas exchange parameters, cell membrane stability analysis, relative water content, Fv/Fm analysis, and chlorophyll content index analysis. Analysis showed that Kofa has the lowest drought tolerance. We overexpressed Hsp70 in Kofa and Bobwhite (spring wheat). Also, screened four S. bicolor varieties (S579, Etios, 5282, Ji2731) using physiological and molecular parameters to determine which one tolerates drought stress best. We found that S579 is the most drought-tolerant. We successfully isolated the Hsp70 gene from S579. Hsp70 is overexpressed in Kofa and Bobwhite using the constitutive and drought-inducible Port 2.3 promoter. Based on our research, Hsp70 triggers the accumulation of actin and the formation of IML, resulting in improved tolerance to drought stress. These findings suggest that manipulating actin and Hsp70 will improve crop plants drought and salinity stress tolerance. This method can be utilised for any crop plants.
