Nitrogen Nutrition Improves the Potential of Wheat (Triticum aestivum L.) to Alleviate the Effects of Drought Stress during Vegetative Growth Periods

Abstract

Efficient nitrogen (N) nutrition has the potential to alleviate drought stress in crops by maintaining metabolic activities even at low tissue water potential. This study was aimed to understand the potential of N to minimize the effects of drought stress applied/occur during tillering (Feekes stage 2) and jointing (Feekes stage 6) growth stages of wheat by observing the regulations and limitations of physiological activities, crop growth rate during drought periods as well as final grain yields at maturity. In present study, pot cultured plants of a wheat cultivar Yangmai-16 were exposed to three water levels [severe stress at 35–40% field capacity (FC), moderate stress at 55–60% FC and well-watered at 75–80% FC] under two N rates (0.24 g and 0.16 g/kg soil). The results showed that the plants under severe drought stress accompanied by low N exhibited highly downregulated photosynthesis, and chlorophyll (Chl) fluorescence during the drought stress periods, and showed an accelerated grain filling rate with shortened grain filling duration (GFD) at post-anthesis, and reduced grain yields. Severe drought-stressed plants especially at jointing, exhibited lower Chl and Rubisco contents, lower efficiency of photosystem II and greater grain yield reductions. In contrast, drought-stressed plants under higher N showed tolerance to drought stress by maintaining higher leaf water potential, Chl and Rubisco content; lower lipid peroxidation associated with higher superoxide dismutase and ascorbate peroxidase activities during drought periods. The plants under higher N showed delayed senescence, increased GFD and lower grain yield reductions. The results of the study suggested that higher N nutrition contributed to drought tolerance in wheat by maintaining higher photosynthetic activities and antioxidative defense system during vegetative growth periods.

Impact of Nitrogen Addition on Physiological, Crop Total Nitrogen, Efficiencies and Agronomic Traits of the Wheat Crop under Rainfed Conditions

“…Gyuga et al [48] reported that N greatly influences photosynthetic processes, and deficiency of N leads to the declined photosynthesis. Similarly, Abid et al [49] in their findings concluded that management of N nutrition could build drought tolerance in wheat by maintaining higher photosynthetic activities and antioxidative defense system during vegetative growth periods. A primary driving force for dry matter production in photosynthesis; thus, its management through the optimization of N could help to improve dry matter production in the plant.…”

Under drought conditions NaCl improves the nutritional status of the xerophyte Zygophyllum xanthoxylum but not of the glycophyte Arabidopsis thaliana

“…Also, accumulation of ions promotes turgor maintenance, which contributes to increased absorption of water in water‐stressed plants and thereby results in improving drought resistance ( da Silva et al., ). Furthermore, N being an important component of chlorophyll and Rubisco affects the metabolism of the plant under drought stress ( Abid et al., ). Functional activity of the photosynthetic apparatus of leaf largely depends on the availability of N in plants ( Brennan , ).…”

Endophytic Azospirillum for enhancement of growth and yield of wheat

“…Pervious study demonstrated that photosynthetic rate under drought stress is closely related to the chlorophyll and N contents of the leaf (Park and Lee 2003). Previous studies have also reported that low N is the major constraint to wheat yield under drought stress (Madani et al 2010;Abid et al 2016). Nawaz et al (2012) reported that early and late drought stress significantly decreases the N uptake by the wheat.…”

“…Nitrogen nutrition has been elucidated to mitigate drought stress in crops. Nitrogen nutrition maintains metabolic activities of plant even at low tissue water potential (Zlatev and Lidon 2012;Abid et al 2016). Pervious study demonstrated that photosynthetic rate under drought stress is closely related to the chlorophyll and N contents of the leaf (Park and Lee 2003).…”