Improving resistance against terminal drought in bread wheat by exogenous application of proline and gamma‐aminobutyric acid

Abstract

Scarcity of water is a severe constraint, which hinders the wheat productivity worldwide. However, foliage application of osmoprotectants may be useful in reducing the drought‐induced yield losses in wheat (Triticum aestivum L.). In this study, potential of foliage applied osmoprotectants (proline, gamma‐aminobutyric acid) in improving the performance of bread wheat against terminal drought was evaluated. Both proline and gamma‐aminobutyric acid (GABA) were foliage applied at 50, 100 and 150 mg/L at anthesis stage (BBCH‐identification code‐ 61), in two bread wheat cultivars viz. Mairaj‐2008 and BARS‐2009. After 1 week of foliage application of these osmoprotectants, drought was imposed by maintaining the pots at 35% water holding capacity. Imposition of drought caused significant reduction in the grain yield of both tested bread wheat cultivars; nonetheless, foliage applied osmoprotectants at either concentration improved the chlorophyll contents, accumulation of proline, glycinebetaine and total soluble phenolics and reduced the malondialdehyde contents, which resulted in better stay green, maintenance of grain weight and grain number under drought stress, thus resulting in better grain yield, water‐use efficiency and transpiration efficiency in both wheat cultivars. However, foliage applied proline at 150 mg/L, and GABA at 100 mg/L was most effective than other concentrations of these osmoprotectants. Performance of cultivar Mairaj‐2008 was quite better than cultivar BARS‐2009. In crux, foliar application of proline and GABA at pre‐optimized rate can be opted as a shotgun approach to improve the performance of wheat under terminal drought.

Growth and Yield Response of Garlic Genotypes to Foliar Application of γ-Aminobutyric Acid

“…In accordance with our findings, Farooq et al (2017) reported that foliage applied GABA at 100 mg/L was more competent than another concentration 150 mg/L in alleviation of drought stress in two cultivars of bread wheat. Also, Krishnan et al (2013) found that GABA supplementation at 50 mM was reported to be more practical than 70 mM in mitigation the damage in perennial ryegrass grown under water deficit condition.…”

“…The result of our study clearly reported that GABA treatments significantly promoted the endogenous total phenols in garlic (Table 2). In the same context, exogenous GABA promoted the accumulation of phenolic substances in banana fruits, wheat and tomato plants under several types of abiotic stress (Wang et al, 2014;Farooq et al, 2017;Cekiç, 2018). Taken together, positive effect of GABA in increasing the agricultural productivity and mitigation of harmful effect of abiotic stresses probably due to accumulation of total phenols that improves antioxidant defense system, thus improving yield and efficiency of wateruse (Farooq et al, 2017).…”

Nitric oxide, γ‐aminobutyric acid, and mannose pretreatment influence metabolic profiles in white clover under water stress

“…Drought or water deficit inhibits plant growth and decreases crop yield. It has been reported that exogenously applied GABA could effectively alleviate drought‐induced decreases in growth and productivity of crops (Farooq et al ; Rezaei‐Chiyaneh et al ). In response to drought and salt stress, transgenic tobacco expressing a GDP‐D‐mannose pyrophosphorylase gene PpGMP maintained better growth performance (Ai et al ).…”

Exogenous application of allelopathic water extracts helps improving tolerance against terminal heat and drought stresses in bread wheat (Triticum aestivum L. Em. Thell.)

“…Drought stress can affect the wheat growth at any stage; nonetheless, the terminal drought is most destructive regarding its impact on wheat grain yield (Farooq, Hussain, & Siddique, ; Farooq, Nawaz, Chaudhary, Indrasti, & Rehman, ; Farooq, Nawaz, Chaudhary, & Rehman, ; Nawaz, Farooq, Cheema, Yasmeen, & Wahid, ). Terminal drought stress affects the pollination (Ashraf, ), thus reducing the grain set and eventually the grain yield (Nawaz, Farooq, Cheema, Yasmeen, et al., ).…”