Role of two-sided crosstalk between NO and H2S on improvement of mineral homeostasis and antioxidative defense in Sesamum indicwn under lead stress
Role of two-sided crosstalk between NO and H2S on improvement of mineral homeostasis and antioxidative defense in Sesamum indicwn under lead stress
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DOI：
10.1016/j.ecoenv.2017.01.037
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发表时间：
2017-05-01
影响因子：
6.8
通讯作者：
Enteshari, Shekoofeh
中科院分区：
文献类型：
--
作者：
Amooaghaie, Rayhaneh;zangene-madar, Faezeh;Enteshari, Shekoofeh
H_2S和NO是调节植物逆境反应的两种重要气体递质。NO和H_2S之间的串扰在研究中存在矛盾的数据。因此，在本研究中，NO和H2S之间的相互作用的作用进行了评估芝麻的铅耐受性，使用药理学和生化方法。结果表明，铅胁迫降低了植物生长、光合色素含量和Fv/Fm比值，增加了膜脂过氧化和H2 O2含量，提高了内源NO和H2S含量，增强了抗氧化酶（APX除外）活性。此外，大多数矿质离子（K，P，Mg，Fe，Mn和Zn）在地上部和根部的浓度下降。Pb在根中的积累量大于地上部。硫氢化钠（NaHS）和硝普钠（SNP）均能促进铅胁迫下植物的生长、叶绿素和类胡萝卜素含量及PSII效率，减轻氧化损伤，提高抗氧化酶活性，降低脯氨酸含量。此外，NaHS和SNP都显着抑制铅的吸收和转运，从而减少了铅对芝麻植株必需矿物质含量的拮抗作用。NaHS可增加NO的生成，cPTIO可完全逆转NaHS诱导的许多反应。施用SNP也促进了Pb胁迫下植物根系中H2S的释放，但只有部分NO驱动的效应被H2S的清除剂HT部分减弱。这些结果首次提出H2S和NO的双向作用可能通过激活抗氧化系统，减少Pb的吸收和转运，协调矿质营养平衡来提高植物对Pb胁迫的耐受性。
H2S and NO are two important gasotransmitters that modulate stress responses in plants. There are the contradictory data on crosstalk between NO and H2S in the studies. Hence, in the present study, the role of interplay between NO and H2S was assessed on the Pb tolerance of Sesamum indicum using pharmacological and biochemical approaches. Results revealed that Pb stress reduced the plant growth and the content of photosynthetic pigments and Fv/Fm ratio, increased the lipid peroxidation and the H2O2 content, elevated the endogenous contents of nitric oxide (NO), H2S and enhanced the activities of antioxidant enzymes (except APX). Additionally, concentrations of most mineral ions (K, P, Mg, Fe, Mn and Zn) in both shoots and roots decreased. Pb accumulation in roots was more than it in shoots. Both sodium hydrosulfide (NaHS as a donor of H2S) and sodium nitroprusside (SNP as an NO donor) improved the plant growth, the chlorophyll and carotenoid contents and PSII efficiency, reduced oxidative damage, increased the activities of antioxidant enzymes and reduced the proline content in Pb-stressed plants. Furthermore, both NaHS and SNP significantly restricted the uptake and translocation of Pb, thereby minimizing antagonistic effects of Pb on essential mineral contents in sesame plants. NaHS increased the NO generation and many NaHS-induced responses were completely reversed by cPTIO, as the specific NO scavenger. Applying SNP also enhanced H2S release levels in roots of Pb-stressed plants and only some NO-driven effects were partially weakened by hypotuarine (HT), as the scavenger of H2S. These findings proposed for the first time that two-sided interplay between H2S and NO might confer an increased tolerance to Pb stress via activating the antioxidant systems, reducing the uptake and translocation of Pb, and harmonizing the balance of mineral nutrient.