Atmospheric H2S and SO2 as sulfur sources for Brassica juncea and Brassica rapa: Regulation of sulfur uptake and assimilation
Atmospheric H2S and SO2 as sulfur sources for Brassica juncea and Brassica rapa: Regulation of sulfur uptake and assimilation
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DOI：
10.1016/j.envexpbot.2015.12.001
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发表时间：
2016-04-01
影响因子：
5.7
通讯作者：
De Kok, Luit J.
中科院分区：
文献类型：
--
作者：
Aghajanzadeh, Tahereh;Hawkesford, Malcolm J.;De Kok, Luit J.
芥菜型油菜和油菜型油菜能够利用叶面吸收的H_2S和SO_2作为硫源进行生长，导致地上部吸收根系提供的硫的能力下降，从而部分降低了根系吸收硫酸盐的能力。缺乏硫酸盐的植物能够利用叶片吸收的硫化氢和二氧化硫作为唯一的生长来源。然而，H_2S或SO_2胁迫对地上部向根的分配减少和硫酸盐吸收能力的上调几乎没有影响，表明地上部硫的同化作用与根中硫酸盐转运体活性的调节之间的相互作用很差。根转运蛋白活性受原位硫酸盐浓度的调节，而不受水溶性非蛋白硫醇(谷胱甘肽)浓度的调节。芥菜和油菜根部和地上部硫醇水平与硫酸盐还原途径相关酶的转录水平之间也没有直接关系。在硫酸盐充足的植物中，H2S和SO2暴露都导致两种植物地上部APS还原酶的转录水平显著降低。硫酸盐胁迫不仅导致植株地上部和根部APS还原酶的转录水平显著升高，而且导致地上部的三磷酸腺苷硫化酶和APS激酶的转录水平升高。H_2S和SO_2胁迫也降低了缺硫植物根部和地上部APS还原酶的转录水平，但仍显著高于缺硫植物。在硫酸盐充足和硫酸盐缺乏的植物中，H_2S和SO_2胁迫对ATP硫酰化酶、APK激酶和亚硫酸盐还原酶的转录水平没有影响。(C)2015爱思唯尔B.V.保留所有权利。
Brassica juncea and Brassica rapa were able to utilize foliarly absorbed H2S and SO2 as sulfur source for growth and resulted in a decreased sink capacity of the shoot for sulfur supplied by the root and subsequently in a partial decrease in sulfate uptake capacity of the roots. Sulfate-deprived plants were able to utilize foliarly absorbed H2S and SO2 as sole source for growth. However, the decrease in shoot to root partitioning and the upregulated sulfate uptake capacity upon sulfate-deprivation was hardly affected by H2S or SO2 exposure, indicating a poor shoot to root interaction between sulfur assimilation in the shoot and the regulation of the sulfate transporter activity in the root. Root transporter activity was regulated by the in situ sulfate rather than the water-soluble non-protein thiols (glutathione) concentration. There was also no direct relation between the thiol levels and the transcript levels of the enzymes involved in the sulfate reduction pathway in either roots or shoots of B. juncea and B. rapa. In sulfate-sufficient plants, both H2S and SO2 exposure resulted in strongly decreased transcript levels of APS reductase in the shoot of both species. Sulfate deprivation resulted not only in strongly enhanced transcript levels of APS reductase in both shoots and roots of the plants, but also in enhanced transcript levels of ATP sulfurylase and APS kinase in the shoots. H2S and SO2 exposure also resulted in a decrease in transcript levels of APS reductase in the roots and shoots of sulfate-deprived plants, but remained significantly higher than that in sulfate-sufficient plants. The transcript levels of ATP sulfurylase, APK kinase and sulfite reductase were not affected in both sulfate-sufficient and sulfate-deprived plants upon H2S and SO2 exposure. (C) 2015 Elsevier B.V. All rights reserved.