Rhizoglomus intraradicesImproves Plant Growth, Root Morphology and Phytohormone Balance ofRobinia pseudoacaciain Arsenic-Contaminated Soils
Rhizoglomus intraradicesImproves Plant Growth, Root Morphology and Phytohormone Balance ofRobinia pseudoacaciain Arsenic-Contaminated Soils
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根内根球菌改善砷污染土壤中刺槐的植物生长、根形态和植物激素平衡
DOI：
10.3389/fmicb.2020.01428
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发表时间：
2020
影响因子：
5.2
通讯作者：
Chang Qingshan
中科院分区：
文献类型：
--
作者：
Zhang QiaoMing;Gong Minggui;Liu Kaiyang;Chen Yanlan;Yuan Jiangfeng;Chang Qingshan
丛枝菌根真菌（AMF）可以提高植物对重金属胁迫的抗性。然而，接种AMF的木本豆科植物对砷（As）的抗性机制尚不清楚。本研究以刺槐（Robinia pseudoacacia L.）在3种不同砷胁迫水平（0、100和200 mg As kg-1土）下，在接种或不接种AMF根内根丛枝菌（Rhizoglomus intraradices）的盆栽土壤中培养幼苗4个月。研究了AM真菌对砷胁迫下植物生长、根系形态、内源激素和土壤球囊霉素含量及比值的影响。由于胁迫毒害抑制了AM真菌孢子的萌发和定殖，抑制了植物的生长，降低了土壤中球囊霉素的含量，改变了植物根系的形态特征和内源激素水平的平衡。然而，R.根内接种提高了所有As处理的地上部和根干重、总根长、根表面积、根体积以及根叉和根尖的数量。R.根内接种显著降低了0 ~ 0.2mm直径级的根长百分率，提高了0.5 ~ 1.0 mm和>1.0 mm直径级的根长百分率，0.2 ~ 0.5mm直径级的根长百分率受R.根内接种易提取的球囊霉素相关蛋白（EE-GRSP）和总球囊霉素相关蛋白（T-GRSP）的含量在R.根内接种的幼苗比未接种的幼苗生长更快。此外，R.根内接种提高了吲哚乙酸（IAA）和脱落酸（阿坝）的含量，降低了赤霉素（GA）和玉米素核苷（ZR）的含量。结果表明，在不同的生长发育时期，不同的生长发育时期，不同的生长发育时期。根内接种的幼苗比未接种的幼苗中的那些低。这些结果表明，R.根内处理减轻了砷对红蜘蛛的毒害作用。通过促进刺槐幼苗生长、改变根系形态、调节植物激素的浓度和比例、提高土壤球囊霉素浓度等方法，结果表明，接种AMF的R.刺槐幼苗是砷污染土壤植被恢复和土壤发育的关键因素。
Arbuscular mycorrhizal fungi (AMF) are known to improve the resistance of host plants against various heavy metal stresses. However, the arsenic (As) resistance mechanism of AMF-inoculated woody legumes remains unclear. In this study, black locust (Robinia pseudoacacia L.) seedlings were cultivated in potted soils inoculated with or without AMF Rhizoglomus intraradices under three different levels of As stress (0, 100, and 200 mg As kg–1 soil) over 4 months. The objective of this paper was to investigate the effects of AMF on plant growth, root morphology, and the content and ratio of endogenous phytohormones and soil glomalin under As stress condition. As stress toxicity suppressed the AM spore germination and colonization, plant growth, and the content of soil glomalin and changed the morphological characteristics of the roots and the balance of endogenous hormone levels in plants. However, R. intraradices inoculation improved the shoot and root dry weights, total root length, root surface area, root volume, and the number of root forks and tips across all As treatments. R. intraradices inoculation obviously decreased the percentage of root length in the 0- to 0.2-mm diameter class and increased those in the 0.5- to 1.0-mm and >1.0-mm diameter classes; the percentages in the 0.2- to 0.5-mm diameter class were less affected by R. intraradices inoculation. The concentrations of the easily extractable glomalin-related (EE-GRSP) and total glomalin-related soil protein (T-GRSP) were higher in the of R. intraradices-inoculated seedlings than those in the non-inoculated seedlings. Furthermore, R. intraradices inoculation increased the concentrations of indole-3-acetic acid (IAA) and abscisic acid (ABA), but decreased the concentrations of gibberellic acid (GA) and zeatin riboside (ZR). The phytohormone ratios of IAA/ABA, GA/ABA, ZR/ABA, and (IAA + GA + ZR)/IAA in the R. intraradices-inoculated seedlings were lower than those in the non-inoculated seedlings. These results indicated that R. intraradices alleviated As toxicity in R. pseudoacacia seedlings by improving their plant growth, altering root morphology, regulating the concentrations and ratios of phytohormones, and increasing the concentration of soil glomalin. The results suggested that AMF-inoculated R. pseudoacacia seedlings would be a critical factor in successful vegetation restoration and soil development in As-contaminated soils.