Cadmium stress inhibits the growth of primary roots by interfering auxin homeostasis in Sorghum bicolor seedlings
Cadmium stress inhibits the growth of primary roots by interfering auxin homeostasis in Sorghum bicolor seedlings
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DOI：
10.1007/s12374-017-0024-0
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发表时间：
2017-12
影响因子：
2.9
通讯作者：
Yi-hua Zhan;Cheng-hao Zhang;Qiu-xun Zheng;Zong-an Huang;Chen Yu
中科院分区：
文献类型：
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作者：
Yi-hua Zhan;Cheng-hao Zhang;Qiu-xun Zheng;Zong-an Huang;Chen Yu
重金属镉（Cd）对植物的毒害效应已被广泛研究。生长素在植物发育的许多方面起着重要作用。本研究分析了镉胁迫下二色Sorbicolor根系生长与生长素信号的关系。Cd胁迫显著降低了双色草幼苗的根伸长、芽长和最大光化学效率（Fv/Fm）。镉被发现主要局限于分生区使用镉染色方法。EdU（乙炔脱氧尿苷）分析表明，镉胁迫显著影响根尖细胞周期进程。Cd胁迫下，根中IAA含量显著降低。双色，且沿着IAA氧化酶活性的增加。生长素转运抑制剂1-萘氧乙酸（1-NOA）或1-萘甲酰胺酸（NPA）显著降低了植物对Cd胁迫的耐受性，而外源1-萘乙酸（NAA）则提高了双色草幼苗对Cd的耐受性。镉胁迫改变了一些生长素生物合成基因的转录水平。此外，NAA干扰镉诱导的活性氧（ROS）的稳态。说明Cd胁迫对S.通过影响生长素和活性氧的稳态来影响双色苗的生长。
Phytotoxic effects of cadmium (Cd), a heavy metal pollutant, on plants have been extensively examined. Auxin plays vital roles in many aspects of plant development. The association between root growth and auxin signaling in Cd-stressedSorghum bicolorwas analyzed in our study. Root elongation, shoot length and the maximal photochemical efficiency (Fv/Fm) inS. bicolorseedlings were dramatically reduced after Cd stress treatment. Cd was found to be predominantly confined in the meristematic zone using a Cd-staining method. Cd stress remarkably influenced the cell cycle progression at the root tip as shown by EdU (ethynyl deoxyuridine) assay. The content of IAA was markedly diminished in the roots of Cd-stressedS. bicolor, which was along with the increase of IAA oxidase activity. Auxin transport inhibitors, 1-naphthoxyacetic acid (1-NOA) or 1- naphthylphthalamic acid (NPA), greatly reduced plant tolerance to Cd stress, whereas exogenous application of 1-naphthaleneacetic acid (NAA) improved Cd tolerance inS. bicolorseedlings. Cd stress altered the transcript level of some putative auxin biosynthetic genes. In addition, NAA interfered with the homeostasis of Cd-induced reactive oxygen species (ROS). These results revealed that Cd stress disturbed the growth ofS. bicolorseedlings by affecting the homeostasis of auxin and ROS.