Use of ABA Treatment for the Activation of Drought Protective Mechanisms in Barley Under Non-stress Conditions

Abstract

) at the early stage of the plant development. We used RIA method, instantaneous water use effi ciency (WUE), the discrimination of 13 C (Δ 13 C) and the expression levels of Dhn4 gene. The increase of ABA concentration in leaves a er exogenous ABA application was detected in all tested genotypes; however, the lowest amount was found in the most tolerant genotype. Increased level of the instantaneous WUE a er ABA treatment was found in all genotypes. The Δ 13 C in ABA treated plants decreased, however, relatively drought-tolerant genotype Tadmor showed lower discrimination even in control variant. The genotype-dependent diff erences were observed in the expression levels of Dhn4 gene in the leaves. High expression level of this gene was observed in Tadmor. Based on the exogenous ABA level, it was possible to distinguish two types of response of plants to exogenous ABA. Tadmor represented one of them as manifesting high sensitivity to exogenous ABA, leading to fast induction of Dhn4 gene relative expression. Conversely, spring genotypes of Jersey and Malz manifested slower response to exogenous ABA as well as lower WUE values and relative expression of Dhn4. The results supported the idea that ABA application may activate similar stress reactions in plants as drought conditions and additionally the intensity of this reaction is genotype dependent.

Assessing Field Prunus Genotypes for Drought Responsive Potential by Carbon Isotope Discrimination and Promoter Analysis

“…Sivamani et al [80] confirmed an improvement of biomass and WUE in transgenic barley plants expressing HVA1 gene under drought conditions. Furthermore, Melišová et al [33] suggested that elevated expression of the HvDhn4 gene, which is also a Y n SK n -type dehydrin and similar to PpDhn2, was associated with the high WUE observed in a drought-tolerant variety of barley at 12 h after ABA treatment. Moreover, DREB TFs improved tolerance to abiotic stress in transgenic plants by regulation of genes involved in abiotic stress responses, so DREB TFs could increase WUE under water deficit conditions [81].…”

“…Carbon isotope discrimination (∆ 13 C) analysis is suggested as an appropriate indicator of long-term WUE at the leaf level [28,32]. The basis of this indirect method has been extensively studied [32][33][34] and suggests a negative correlation between WUE and ∆ 13 C. Furthermore, the relationship between ∆ 13 C and ash content has been studied in cereals [35,36], apple [37] and peach [38] in order to improve phenotyping and breeding for WUE. The association among these three parameters (WUE, ∆ 13 C and leaf ash content) is based on the passive transport of minerals via the xylem and their accumulation in growing and transpiring tissues.…”