Drought-induced alterations in photosynthetic, ultrastructural and biochemical traits of contrasting sugarcane genotypes

Abstract

Drought is an important factor which limits growth of sugarcane. To elucidate the physiological and biochemical mechanisms of tolerance, a pot experiment was conducted at Sugarcane Research Institute, Kaiyuan, China. Two genotypes (Yuetang 93-159-sensitive and Yunzhe 05-51-tolerant), were subjected to three treatments; 70±5% (control), 50±5% (moderate drought) and 30±5% (severe drought) of soil field capacity. The results demonstrated that drought induced considerable decline in morpho-physiological, biochemical and anatomical parameters of both genotypes, with more pronounced detrimental effects on Yuetang 93-159 than on Yunzhe 05-51. Yunzhe 05-51 exhibited more tolerance by showing higher dry biomass, photosynthesis and antioxidant enzyme activities. Compared with Yuetang 93-159, Yunzhe 05-51 exhibited higher soluble sugar, soluble protein and proline contents under stress. Yunzhe 05-51 illustrated comparatively well-composed chloroplast structure under drought stress. It is concluded that the tolerance of Yunzhe 05-51 was attributed to improved antioxidant activities, osmolyte accumulation and enhanced photosynthesis. These findings may provide valuable information for future studies on molecular mechanism of tolerance.

Drought tolerance inBrassica napusis accompanied with enhanced antioxidative protection, photosynthetic and hormonal regulation at seedling stage

“…Drought stress treatment significantly tempered the leaf gas exchange parameters (Pn, Gs, and Tr), while considerable reductions in Pn and Gs were observed in the sensitive cultivar (GY605) upon drought stress compared to control (Table 1), which correspond to previous studies on drought stress (Demirel et al, 2020). The decrease in gas exchange parameters may be due to the photosynthetic pigment's degradation and distortion of water transport from root to shoot, which further reduced the Gs and Tr, that is accompanied with a reduction of Pn (Zhang et al, 2020). Previous studies have indicated that leaf Tr exhibits a positive relation with drought stress, which may cause stomatal closure to reduce Tr to maintain water balance under drought stress (Li et al, 2017).…”

Seed Germination Behavior, Growth, Physiology and Antioxidant Metabolism of Four Contrasting Cultivars under Combined Drought and Salinity in Soybean

“…To counteract the oxidative damage induced by ROS, plants normally upregulate antioxidative defense and antioxidant enzymes [14]. Previous research revealed that enzymatic antioxidants play important roles in stress resistance and respond as a defense mechanism in plants [15]. Hence, plants with a stronger antioxidant defense system may be more stress resistant.…”

Abiotic Stress Triggers the Expression of Genes Involved in Protein Storage Vacuole and Exocyst-Mediated Routes

“…As previously discussed, during their life cycle, plants can be exposed to several adverse environmental conditions, including salinity, drought, extreme temperatures, and metal poisoning, commonly characterised as abiotic stresses. These conditions will affect several molecular, biochemical and physiological processes resulting in developmental delays and eventually senescence and cell death [36][37][38]. Because plants are immobile organisms that cannot respond to environmental stimuli like animals, developing adequate responses at the cellular level is crucial.…”