Project description:Drought is a major environmental stress that limits growth and development of cool-season annual grasses. Drought transcriptional profiles of resistant and susceptible lines were studied to understand the molecular mechanisms of drought tolerance in annual ryegrass (Lolium multiflorum L.). A total of 4,718 genes exhibited significant differential expression in two L. multiflorum lines. Additionally, up-regulated genes associated with drought response in the resistant lines were compared with susceptible lines. Gene ontology enrichment and pathway analyses revealed that genes partially encoding drought-responsive proteins as key regulators were significantly involved in carbon metabolism, lipid metabolism, and signal transduction. Comparable gene expression was used to identify the genes that contribute to the high drought tolerance in resistant lines of L. multiflorum.
Project description:Heavy metal cadmium (Cd) affects seriously crop growth, quality and yield, and has potential threats to human safety. We found the difference of two ryegrasses (Lolium multiflorum Lam.), a high-Cd tolerance (LmHC) and a low-Cd tolerance (LmLC) cultivars , in response to cadmium stress. The germination rate, plant growth, and fresh weight of LmHC were much better than that of LmLC. So we use RNA sequencing to investigate the differentially expressed genes(DEGs) about cadmium response between LmHC and LmLC. Real-time quantitative PCR analysis showed that the same DEGs of LmLC and LmHC had obviously difference expression level under Cd treatment. It was suggestion that differential expression of DEGs might be involved in regulating Cd tolerance, accumulation and translocation.These results will be helpful for understanding the underlying molecular mechanism in Cd toxicity and provide references for improving the ecological environment through genetic improvement.
Project description:Frost tolerance is the main component of winter-hardiness. To express this trait, plants have to sense low temperature, and respond by activating the process of cold acclimation. The molecular mechanisms of this acclimation have not been fully understood in the agronomically important group of forage grasses, including Lolium-Festuca species. Herein, the introgression forms of L. multiflorum/F. arundinacea distinct with respect to their frost tolerance, were used as models for the comprehensive, proteomic and physiological, research to recognize the crucial components of cold acclimation in forage grasses. The obtained results stressed the importance of photosynthetic performance under acclimation to low temperature. The stable level of photochemical processes after three weeks of cold acclimation in the introgression form with a higher level of frost tolerance, combined simultaneously with the stable level of CO2 assimilation after that period, despite decreased stomatal conductance, indicated the capacity for that form to acclimate its photosynthetic apparatus to low temperature. This phenomenon was driven by the Calvin cycle efficiency, associated with revealed here accumulation profiles and activities of chloroplastic aldolase. The capacity to acclimate the photosynthetic machinery to cold could be one of the most crucial components of forage grass metabolism to improve frost tolerance.
