Water deficit induced physiological and amino acid responses in some rice varieties using NMR‐metabolic analysis

Abstract

Deficit irrigation (DI) is a choice made by producers to improve water productivity and might be highly preferred in future production programs in arid regions. Identifying DI-tolerant cultivars will be critical to improve rice (Oryza sativa L.) productivity under the future climate change conditions. Nuclear magnetic resonance (NMR)-based metabolomics is a recent technique that has received less attention so far and can be used to compare genetic differences in DI tolerance. For this purpose, field experiments were carried out during two successive summer seasons in Egypt to compare genetic differences for water deficit tolerance in seven rice genotypes using NMR technique. The genotypes Azucena and IRAT 170 achieved the best values of water productivity (WP) under DI, recording 1.79 and 0.99 kg m -3 respectively, confirming their suitability in the water deficit breeding program to produce new promising lines and to keep yield potential stable under climate change conditions. The PLS-DA of 1H-NMR spectra showed a clear separation between genotypes under both full irrigation (FI) and DI conditions. Quantitative analysis showed that sucrose, threonine, glutamate, and allantoin were accumulated at DI when compared to FI conditions, and these metabolite compounds may be closely related to DI conditions. Tryptophan, as an aromatic amino acid, has increased across cultivars, most dramatically in Azucena and IRAT 170. Tyrosine and phenylalanine also increased in Azucena and IRAT 170, but not as dramatically as tryptophan. The rice genotypes Azucena and IRAT 170 could be successfully recommended for higher yields and quality under DI conditions.

A metabolomic snapshot through NMR revealed differences in phase transition during the induction of reproduction in Ulva ohnoi (Chlorophyta)

“…The initial response to give protection against dehydration stress may be an increase in sugar. 50 In some plants, glutamate is crucial for seed germination, pollen germination, root architectures and in dealing with various environmental stresses. 51 Glutamate and pyruvate react to generate alanine and ketoglutarate via an alanine aminotransferase reaction.…”

The Responses of Physiological Characteristics and Flowering Related Gene to the Different Water Stress Levels of Red-Flesh Pummelo Cultivars (Citrus grandis (L.) Osbeck) Own-Rooted by Air Layering Propagation under Two Growing Conditions

“…In addition, the phenomenon of stomata closure or low SC normally occurs in order to reduce transpiration and can be used as an indicator of plant water status [48,49]. Meanwhile, stomatal closure decreases photosynthesis under water stress [28,29,50]. Furthermore, CF has been generally used as an indicator of photochemical efficiency [51].…”

“…Besides, severe water stress produced maximum flowering capacity compared to mild water stress in the Tahiti lime (Citrus latifolia) [21]. The water stress or water deficit stressful conditions may degrade necessary physiological processes such as stomatal conductance, photosynthesis, and nitrogen uptake [22][23][24][25][26][27][28][29]. A major reduction in chlorophyll fluorescence was also caused by water deficiency, suggest-ing photosynthesis inhibition [30].…”