Sulfur metabolism, organic acid accumulation and phytohormone regulation are crucial physiological processes modulating the different tolerance to Pb stress of two contrasting poplars
Sulfur metabolism, organic acid accumulation and phytohormone regulation are crucial physiological processes modulating the different tolerance to Pb stress of two contrasting poplars
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硫代谢、有机酸积累和植物激素调节是调节两种对比杨树对铅胁迫不同耐受性的关键生理过程
DOI：
10.1093/treephys/tpac033
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发表时间：
2022
期刊：
影响因子：
4
通讯作者：
Zhi-Bin Luo
中科院分区：
文献类型：
--
作者：
Wenguang Shi;Jing Li;Donxu Kan;Wenjian Yu;Xin Chen;Yuhong Zhang;Chaofeng Ma;Shurong Deng;Jing Zhou;Payam Fayyaz;Zhi-Bin Luo
抽象的。为探讨杨树耐铅的关键生理过程，以铅敏感性高的灰杨和铅敏感性低的黑杨为对照，用0和8mM铅处理6周。Pb被两种白杨根系吸收并在根和叶中大量积累，导致活性氧（ROS）过量产生，光合作用和生物量降低。其中，灰黑杨的耐受指数（TI）显著低于黑杨。此外，两种白杨根和叶中营养元素、硫醇、有机酸、植物激素和非酶抗氧化剂的浓度以及抗氧化酶活性等生理反应也存在差异。两种白杨的营养元素、有机酸和植物激素含量差异显著。进一步评价了与铅胁迫相关的生理过程，结果表明，灰毛白杨根系的“硫代谢”变化幅度较大，而根系的“有机酸积累”和叶片的“激素调节”变化幅度明显小于黑杨。这些结果表明，灰毛杨和黑杨对Pb胁迫的生理反应存在差异，硫代谢、有机酸积累和植物激素调节可能是影响两种白杨对Pb胁迫耐受能力差异的关键生理过程。
Abstract. To investigate the pivotal physiological processes modulating lead (Pb) tolerance capacities of poplars, the saplings of two contrasting poplar species, Populus × canescens with high Pb sensitivity and P. nigra with relatively low Pb sensitivity, were treated with either 0 or 8mM Pb for 6weeks. Pb was absorbed by the roots and accumulated massively in the roots and leaves, leading to overproduction of reactive oxygen species (ROS), reduced photosynthesis and biomass in both poplar species. Particularly, the tolerance index (TI) of P. × canescens was significantly lower than that of P. nigra. Moreover, the physiological responses including the concentrations of nutrient elements, thiols, organic acids, phytohormones and non-enzymatic antioxidants, and the activities of antioxidative enzymes in the roots and leaves were different between the two poplar species. Notably, the differences in concentrations of nutrient elements, organic acids and phytohormones were remarkable between the two poplar species. A further evaluation of the Pb-tolerance-related physiological processes showed that the change of ‘sulfur metabolism’ in the roots were greater, and that of ‘organic acid accumulation’ in the roots and ‘phytohormone regulation’ in the leaves were markedly smaller in P. × canescens than those in P. nigra. These results suggest that there are differences in Pb tolerance capacities between P. × canescens and P. nigra, which is probably associated with their contrasting physiological responses to Pb stress, and that sulfur metabolism, organic acid accumulation, and phytohormone regulation are probable the key physiological processes modulating the different Pb tolerance capacities between the two poplar species.