Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
MOE Key Laboratory of Biosystems Homeostasis & Protection, Institute of Microbiology, College of Life Science, Zhejiang University, Hangzhou 310058, China.
J Hazard Mater. 2022 Sep 5;437:129429. doi: 10.1016/j.jhazmat.2022.129429. Epub 2022 Jun 20.
Due to the high migration capacity in agricultural soil-crop systems, cadmium (Cd) is accumulated in various crops and severely inhibits plant growth. In this study, we showed that, under Cd stress, the plant-symbiotic fungus Metarhizium robertsii reduced Cd accumulation in Arabidopsis thaliana shoots and roots by 21.8 % and 23.8 %, respectively. This is achieved by M. robertsii colonization-induced elevation of Cd efflux capacity via upregulation of three PCR genes, which is confirmed by the fact that the extent to which M. robertsii reduced Cd accumulation in the WT plants was greater than the inactivating mutants of the PCR genes. M. robertsii also alleviated Cd-induced leaf etiolation in A. thaliana by increasing the chlorophyll amount and modified plant physiological status to increase Cd stress tolerance via increasing production of catalase, peroxidase and glutathione and upregulating multiple HIPP proteins involved in sequestration of Cd. Notably, consistent with that in A. thaliana, the colonization of M. robertsii also reduced the Cd accumulation in Oryza sativa seedlings by upregulating the PCR gene OsPCR1, and increased chlorophyll amount and alleviated oxidative stress. Therefore, M. robertsii colonization reduced Cd accumulation in plants, and promoted plant growth and health by elevating Cd efflux capacity and modifying physiological status.
由于农业土壤-作物系统中的高迁移能力，镉（Cd）在各种作物中积累，并严重抑制植物生长。在这项研究中，我们表明，在 Cd 胁迫下，植物共生真菌玫烟色棒束孢通过上调三个 PCR 基因，分别将拟南芥地上部和根部的 Cd 积累降低了 21.8%和 23.8%。这是通过玫烟色棒束孢定殖诱导的 Cd 外排能力升高实现的，这一事实证实了玫烟色棒束孢在 WT 植物中降低 Cd 积累的程度大于 PCR 基因失活突变体。玫烟色棒束孢还通过增加过氧化氢酶、过氧化物酶和谷胱甘肽的产生以及上调参与 Cd 螯合的多个 HIPP 蛋白，来增加叶绿素含量和改变植物生理状态，从而提高 Cd 胁迫耐受性，从而缓解 Cd 诱导的拟南芥叶片黄化。值得注意的是，与在拟南芥中一样，玫烟色棒束孢的定殖也通过上调 PCR 基因 OsPCR1 降低了水稻幼苗中的 Cd 积累，并增加了叶绿素含量，缓解了氧化应激。因此，玫烟色棒束孢的定殖降低了植物中的 Cd 积累，并通过提高 Cd 外排能力和改变生理状态来促进植物生长和健康。
