Comparative physiological analysis in the tolerance to salinity and drought individual and combination in two cotton genotypes with contrasting salt tolerance
Comparative physiological analysis in the tolerance to salinity and drought individual and combination in two cotton genotypes with contrasting salt tolerance
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DOI：
10.1111/ppl.12791
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发表时间：
2019-02-01
影响因子：
6.4
通讯作者：
Wu, Feibo
中科院分区：
文献类型：
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作者：
Ibrahim, Wasim;Qiu, Cheng-Wei;Wu, Feibo
土壤盐分和干旱是限制棉花生长和产量的两种最常见和最常见的共存非生物胁迫。然而，对这种情况的耐受的生理机制仍然难以捉摸。通过温室盆栽试验，研究了耐盐棉花品种中棉23(耐盐)和中棉41(盐敏感)对单一干旱(4%土壤水分；D)、盐分(200 mMNaC l；S)胁迫和复合胁迫(D+S)的响应差异。结果表明，干旱和盐分胁迫单独或联合胁迫对两种棉花品种的植株生长、叶绿素含量和光合作用均有显著影响，其中复合胁迫的影响最大。值得注意的是，在3种胁迫下，中棉23的植株干重、光合作用和超氧化物歧化酶(SOD)、过氧化氢酶(POD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)等抗氧化物酶活性均高于对照，而盐胁迫下中棉41的上述指标显著低于对照。在盐分胁迫下，中棉23的Na+/K+-ATPase活性高于中棉41。然而，在单一干旱胁迫和D+S胁迫下，两个基因型之间没有显著差异。盐分胁迫下，中棉41的Ca~(2+)/Mg~(2+)-ATPase活性差异不显著，而中棉23的Ca~(2+)/Mg~(2+)-ATPase活性显著升高。此外，与中棉41相比，中棉23在3种胁迫下积累了更多的可溶性糖、甘氨酸甜菜碱和K+，但积累的Na+较少。两种棉花品种的叶尖和根尖细胞超微结构均发生了明显变化。但中棉23受盐胁迫的影响小于中棉41，尤其是在盐分胁迫下。这些结果为揭示干旱和盐分胁迫对棉花品种的单一和复合效应机制提供了新的思路。
Soil salinity and drought are the two most common and frequently co-occurring abiotic stresses limiting cotton growth and productivity. However, physiological mechanisms of tolerance to such condition remain elusive. Greenhouse pot experiments were performed to study genotypic differences in response to single drought (4% soil moisture; D) and salinity (200mM NaCl; S) stress and combined stresses (D+S) using two cotton genotypes Zhongmian 23 (salt-tolerant) and Zhongmian 41 (salt-sensitive). Our results showed that drought and salinity stresses, alone or in combination, caused significant reduction in plant growth, chlorophyll content and photosynthesis in the two cotton genotypes, with the largest impact visible under combined stress. Interestingly, Zhongmian 23 was more tolerant than Zhongmian 41 under the three stresses and displayed higher plant dry weight, photosynthesis and antioxidant enzymes activities such as superoxide dismutase (SOD), peroxidase (POD) catalase (CAT) and ascorbate peroxidase (APX) activities compared to control, while those parameters were significantly decreased in salt-stresses Zhongmian 41 compared to control. Moreover, Na+/K+-ATPase activity was more enhanced in Zhongmian 23 than in Zhongmian 41 under salinity stress. However, under single drought stress and D+S stress no significant differences were observed between the two genotypes. No significant differences were detected in Ca2+/Mg2+-ATPase activity in Zhongmian 41, while in Zhongmian 23 it was increased under salinity stress. Furthermore, Zhongmian 23 accumulated more soluble sugar, glycine-betaine and K+, but less Na+ under the three stresses compared with Zhongmian 41. Obvious changes in leaf and root tips cell ultrastructure was observed in the two cotton genotypes. However, Zhongmian 23 was less affected than Zhongmian 41 especially under salinity stress. These results give a novel insight into the mechanisms of single and combined effects of drought and salinity stresses on cotton genotypes.