The Effect of Abiotic Stresses on the Protein Composition of Four Hungarian Wheat Varieties

Metabolic and transcriptomic profiling during wheat seed development under progressive drought conditions

Globally, bread wheat (Triticum aestivum) is one of the most important staple foods; when exposed to drought, wheat yields decline. Although much research has been performed to generate higher yield wheat cultivars, there have been few studies on improving end-product quality under drought stress, even though wheat is processed into flour to produce so many foods, such as bread, noodles, pancakes, cakes, and cookies. Recently, wheat cultivation has been affected by severe drought caused by global climate change. In previous studies, seed shrinkage was observed in wheat exposed to continuous drought stress during seed development. In this study, we investigated how progressive drought stress affected seed development by metabolomic and transcriptomic analyses. Metabolite profiling revealed the drought-sensitive line reduced accumulation of proline and sugar compared with the water-saving, drought-tolerant transgenic line overexpressing the abscisic acid receptor TaPYL4 under drought conditions in spikelets with developing seeds. Meanwhile, the expressions of genes involved in translation, starch biosynthesis, and proline and arginine biosynthesis was downregulated in the drought-sensitive line. These findings suggest that seed shrinkage, exemplifying a deficiency in endosperm, arose from the hindered biosynthesis of crucial components including seed storage proteins, starch, amino acids, and sugars, ultimately leading to their inadequate accumulation within spikelets. Water-saving drought tolerant traits of wheat would aid in supporting seed formation under drought conditions.

Responses of maize hybrids to water stress conditions at different developmental stages: accumulation of reactive oxygen species, activity of enzymatic antioxidants and degradation in kernel quality traits

Sustainable maize production under changing climatic conditions, especially heat and water stress conditions is one of the key challenges that need to be addressed immediately. The current field study was designed to evaluate the impact of water stress on morpho-physiological, biochemical, reactive oxygen species, antioxidant activity and kernel quality traits at different plant growth stages in maize hybrids. Four indigenous i.e., YH-5427, YH-5482, YH-5395, JPL-1908, and one multinational maize hybrid i.e., NK-8441 (Syngenta Seeds) were used for the study. Four stress treatments (i) Control (ii) 3-week water stress at pre-flowering stage (iii) 3-week water stress at anthesis stage (iv) 3-week water stress at grain filling/post-anthesis stage. The presence of significant oxidative stress was revealed by the overproduction of reactive oxygen species (ROXs) i.e., H2O2 (1.9 to 5.8 µmole g−1 FW) and malondialdehyde (120.5 to 169.0 nmole g−1 FW) leading to severe negative impacts on kernel yield. Moreover, a severe reduction in photosynthetic ability (50.6%, from 34.0 to 16.8 µmole m−2 s−1), lower transpirational rate (31.3%, from 3.2 to 2.2 mmol m−2 s−1), alterations in plant anatomy, reduced pigments stability, and deterioration of kernel quality was attributed to water stress. Water stress affected all the three studied growth stages, the pre-flowering stage being the most vulnerable while the post-anthesis stage was the least affected stage to drought stress. Antioxidant activity was observed to increase under all stress conditions in all maize hybrids, however, the highest antioxidant activity was recorded at the anthesis stage and in maize hybrids YH-5427 i.e., T-SOD activity was increased by 61.3% from 37.5 U mg−1 pro to 60.5 U mg−1 pro while CAT activity was maximum under water stress conditions 8.3 U mg−1 pro as compared to 10.3 U mg−1 pro under control (19.3%). The overall performance of maize hybrid YH-5427 was much more promising than other hybrids, attributed to its higher photosynthetic activity, and better antioxidant defense mechanism. Therefore, this hybrid could be recommended for cultivation in drought-prone areas.