Insights into Metabolic Reactions of Semi-Dwarf, Barley Brassinosteroid Mutants to Drought

Abstract

The roles of endogenous brassinosteroids (BRs) in the modulation of reaction to drought and genetic regulation of this process are still obscure. In this study, a multidirectional analysis was performed on semi-dwarf barley (Hordeum vulgare) Near-Isogenic Lines (NILs) and the reference cultivar “Bowman” to get insights into various aspects of metabolic reaction to drought. The NILs are defective in BR biosynthesis or signaling and displayed an enhanced tolerance to drought. The BR metabolism perturbations affected the glucose and fructose accumulation under the control and stress conditions. The BR metabolism abnormalities negatively affected the sucrose accumulation as well. However, during drought, the BR-deficient NILs accumulated higher contents of sucrose than the “Bowman” cultivar. Under the control conditions, accumulation of transcripts encoding antioxidant enzymes ascorbate peroxidase (HvAPX) and superoxide dismutase (HvSOD) was BR-dependent. However, during drought, the accumulation of HvAPX transcript was BR-dependent, whereas accumulations of transcripts encoding catalase (HvCAT) and HvSOD were not affected by the BR metabolism perturbations. The obtained results reveal a significant role of BRs in regulation of the HvAPX and HvCAT enzymatic activities under control conditions and the HvAPX and HvSOD activities during physiological reactions to drought.

Impact of Drought Exerted during Spike Development on Tillering, Yield Parameters and Grain Chemical Composition in Semi-Dwarf Barley Mutants Deficient in the Brassinosteroid Metabolism

“…In the case of the semi-dwarf, erect line BW312 which along with other BR-related semi-dwarf NILs showed improved tolerance to drought in our previous studies [16,18], and in this study displayed the highest values of the productive tillering and the average grain weight per plant (under the drought conditions), there may be an additional opportunity for yield increase through higher planting density and improved drought tolerance. Therefore, the BW312 line, which represents the new allele of the HvBRI1 (Uzu1) gene-uzu1.b, may constitute an alternative in future barley breeding programs, taking into account the ongoing climate change and necessity of developing new drought-tolerant crop cultivars.…”

“…It was postulated that modifications of plant architecture by manipulating the BR biosynthesis or signaling may be a feasible approach for improving crop yield [12]. Importantly, recent reports in the dicot and monocot model species Arabidopsis thaliana (thale cress) and Brachypodium distachyon (purple false brome), as well as in the important crops Oryza sativa (rice) and Hordeum vulgare (barley) indicated that mutants defective in the BR metabolism show a various degree of plant height reduction and an enhanced tolerance to drought [13][14][15][16][17][18]. It is known that cereal crops adapt to drought by decreasing their leaf size and delaying flowering [19].…”

iTRAQ-based quantitative proteome analysis insights into cold stress of Winter Rapeseed (Brassica rapa L.) grown in the field

“…The samples were analyzed in triplicates. POD activity 54 , CAT activity 54 , SS content 55 , IAA content 56 , SP and MDA content 57 were analyzed as indicators of physiological response. The majuscules indicated a significant difference (p < 0.05) for the freezing stress-treated samples compared with chilling stressed samples.…”

iTRAQ-Based Quantitative Proteome Analysis Insights into Cold Stress of Winter Turnip Rapa (Brassica rapa L.) Grown in the Field

“…The samples were performed three times with similar results. POD activity [51], CAT activity [52], SS content [53], IAA content [54], SP and MDA content [55] were analyzed as indicators of physiological response. The majuscules indicated a significant difference (p < 0.01) for the freezing stress-treated samples compared with chilling stressed samples.…”