-Aminobutyric acid increases abscisic acid accumulation and desiccation tolerance and decreases water use but fails to improve grain yield in two spring wheat cultivars under soil drying

Abstract

A pot experiment was conducted to investigate the effect of the non-protein amino acid, β-aminobutyric acid (BABA), on the homeostasis between reactive oxygen species (ROS) and antioxidant defence during progressive soil drying, and its relationship with the accumulation of abscisic acid (ABA), water use, grain yield, and desiccation tolerance in two spring wheat (Triticum aestivum L.) cultivars released in different decades and with different yields under drought. Drenching the soil with 100 µM BABA increased drought-induced ABA production, leading to a decrease in the lethal leaf water potential (Ψ) used to measure desiccation tolerance, decreased water use, and increased water use efficiency for grain (WUEG) under moderate water stress. In addition, at severe water stress levels, drenching the soil with BABA reduced ROS production, increased antioxidant enzyme activity, and reduced the oxidative damage to lipid membranes. The data suggest that the addition of BABA triggers ABA accumulation that acts as a non-hydraulic root signal, thereby closing stomata, and reducing water use at moderate stress levels, and also reduces the production of ROS and increases the antioxidant defence enzymes at severe stress levels, thus increasing the desiccation tolerance. However, BABA treatment had no effect on grain yield of wheat when water availability was limited. The results suggest that there are ways of effectively priming the pre-existing defence pathways, in addition to genetic means, to improve the desiccation tolerance and WUEG of wheat.

Old and New Cultivars of Soya Bean (Glycine max L.) Subjected to Soil Drying Differ in Abscisic Acid Accumulation, Water Relations Characteristics and Yield

“…Du et al. (, ) found that exogenous BABA or ABA could induce ABA accumulation in the leaves and stomatal closure earlier and enhance leaf desiccation tolerance in wheat under drought. In our study, the new soya bean cultivars JD and ZH had a higher concentration of ABA in the leaf for the first 10 days after withholding water (Fig.…”

“…() found that exogenous β‐Aminobutyric acid induced earlier stomatal close under drought by accumulation more ABA in the leaves; moreover, more ABA accumulation in the leaves reduced the water loss and improved the leaf water status and desiccation tolerance (Du et al. , ), indicating more leaf ABA accumulation may improve the leaf water status by inducing stomatal close earlier. But, there is little such information in soya bean response to progressive soil drying.…”

Drought Tolerance in Modern and Wild Wheat

“…It was shown that ascorbate processing and oxidation were differentially changed in the two cultivars [7]. Recently several other studies of ROS were performed to determine its role in the drought response network in relation to photosynthesis, NO, root growth, ABA, and BABA ( β -aminobutyric acid) [82, 95, 96]. …”

“…Recently the role of ABA catabolism in drought was supported by direct evidence from a wheat deletion line [63]. ABA is a major hot topic of drought research, and recently several studies are performed to determine its role in drought in relation to several drought-related molecules: protective proteins, NO, ROS, leaf and root growth, osmotic adjustment, BABA, ROS, and antioxidants [79, 82, 86, 95]. Additionally, in a recent study alginate oligosaccharides (AOS) prepared from degradation of alginate were shown to play a role in enhancing drought resistance in T. aestivum growth period by upregulating the drought tolerance related genes involved in ABA signal pathway, such as LEA1, SnRK2, and pyrroline-5-carboxylate synthetase gene (P5CS) [97].…”

Anhydrobiosis and programmed cell death in plants: Commonalities and Differences

“…One of the three homologues of the ABA transcription regulator 'ABA insensitive 3 (ABI3) found in P. patens had been shown to partially complement the Arabidopsis abi3-6 mutant [122]; indicating that ABA-induced protection against desiccation is a conserved mechanism across plant kingdom. In a recent report, accumulation of ABA triggered by ␤-Aminobeuteric acid (BABA) treatment has been shown to act as non-hydraulic root signal resulting in stomatal closure, reduction in ROS production and higher anti-oxidant defence enzymes thus increasing the desiccation-tolerance in wheat cultivar [123].…”