Cytoplasmic glucose-6-phosphate dehydrogenase plays an important role in the silicon-enhanced alkaline tolerance in highland barley
Cytoplasmic glucose-6-phosphate dehydrogenase plays an important role in the silicon-enhanced alkaline tolerance in highland barley
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细胞质葡萄糖-6-磷酸脱氢酶在硅增强青稞耐碱性中发挥重要作用
DOI：
10.1071/fp20084
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发表时间：
2020-08-11
影响因子：
3
通讯作者：
Bi, Yurong
中科院分区：
文献类型：
--
作者：
He, Qiang;Li, Ping;Bi, Yurong
葡萄糖-6-磷酸脱氢酶（G6 PDH）作为戊糖磷酸途径中的关键酶，广泛响应生物和非生物胁迫。本研究旨在探讨G6 PDH在缓解硅胁迫诱导的青稞碱胁迫中的作用。施硅降低了叶片失水量、丙二醛（MDA）和活性氧（ROS）含量，提高了叶片鲜重、光合速率、K+含量、超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活性，缓解了碱胁迫对叶片的伤害。碱胁迫显著提高了G6 PDH活性，特别是胞质G6 PDH活性，外源Si进一步刺激了G6 PDH活性。NaHCO 3和NaHCO 3 + Si处理下，NADPH和还原型谷胱甘肽（GSH）含量与G6 PDH活性变化趋势相似。氨基葡萄糖对G6 PDH活性的抑制作用使Si对碱胁迫的缓解作用消失，表现为活性氧含量的增加和GSH含量的降低。总之，我们的研究结果表明，硅增强碱性胁迫的耐受性可能与细胞质G6 PDH的调节GSH水平在青稞。
Glucose-6-phosphate dehydrogenase (G6PDH), as a key enzyme in the pentose phosphate pathway, extensively responds to the biotic and abiotic stresses. In this study we focussed on the G6PDH role in the alleviation of alkaline stress induced by silicon (Si) in highland barley. Application of Si reduced the water loss and malondialdehyde (MDA) and reactive oxygen species (ROS) contents, improved the fresh weight, photosynthesis, K(+)content, and the superoxide dismutase (SOD) and catalase (CAT) activities, thus alleviating the damage caused by alkaline stress. The G6PDH activity, especially the cytoplasmic G6PDH, significantly increased under alkaline stress, and was further stimulated by the addition of exogenous Si. Meanwhile, the levels of NADPH and reduced glutathione (GSH) showed similar profiles to G6PDH activity under NaHCO(3)and NaHCO3+ Si treatments. The inhibition of G6PDH activity by glucosamine abolished the relieving effect of Si on alkaline stress, which was manifested in the increase of ROS and the decrease of GSH content. Together, our results suggest that Si-enhanced tolerance of alkaline stress may be related to the regulation of GSH levels by the cytoplasmic G6PDH in highland barley.