College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China.
Jiangsu Coastal Area Institute of Agricultural Sciences, Yancheng, Jiangsu, 224002, China.
Ecotoxicol Environ Saf. 2020 Jan 30;188:109935. doi: 10.1016/j.ecoenv.2019.109935. Epub 2019 Nov 15.
Chromium (Cr) is one of the most toxic heavy metals and a health hazard to millions of people worldwide. Ectomycorrhizal (ECM) fungi can assist plants in phytoremediation of heavy metal contaminated soil. Cr tolerance differs among ECM fungal varieties, but the underlying molecular mechanisms of Cr tolerance in ECM fungi are not clear. This study identified, analysed and compared the Cr(VI)-induced transcriptional changes between Cr(VI)-tolerant strain (Pisolithus sp. 1 LS-2017) and Cr(VI)-sensitive strain (Pisolithus sp. 2 LS-2017) by de novo transcriptomic analysis. The results showed that 93,642 assembled unique transcripts representing the 22,353 (46.76%) unigenes matched the proteins we have known in the Nr database and 47,801 unigenes were got from the Pisolithus spp. For DEGs between the control and 10 mg/L Cr(VI) treatment, cyanoamino acid metabolic, type I diabetes mellitus metabolism, nitrogen metabolism and beta-Alanine metabolism pathways were significantly enriched (p < 0.05) in Pisolithus sp. 1 LS-2017. Two nitrate reductase family genes (nidD, niiA) provide Cr(VI) tolerance for Pisolithus sp. 1 LS-2017 by regulating Cr(VI) reduction. In addition, NO produced by nidD, niiA regulated denitrification can alleviate Cr(VI) induced oxidative stress. In Pisolithus sp. 2 LS-2017, the alcC, aldA and lcf2 gene may alleviate Cr(VI) induced oxidative stress by protecting SH groups and increasing secondary metabolism, reducing detoxify aldehydes to carboxylic acids and producing LCPUFAs respectively; .T gene regulate Cr(VI) induced wound healing by pigmentation and stability of melanin in spore; MKP2 gene accelerate Cr(VI) induced cell death and gpmA gene regulated Cr(VI) induced energy emergency.
铬（Cr）是毒性最大的重金属之一，对全球数百万人的健康构成威胁。外生菌根（ECM）真菌可以帮助植物修复重金属污染的土壤。ECM 真菌的 Cr 耐受能力不同，但 ECM 真菌中 Cr 耐受的潜在分子机制尚不清楚。本研究通过从头转录组分析，鉴定、分析和比较了 Cr（VI）耐受菌株（Pisolithus sp.1 LS-2017）和 Cr（VI）敏感菌株（Pisolithus sp.2 LS-2017）之间 Cr（VI）诱导的转录变化。结果表明，93642 个组装的独特转录本代表了 22353 个（46.76%）与我们在 Nr 数据库中已知的蛋白质匹配的 unigenes，47801 个 unigenes来自 Pisolithus spp。对于对照和 10mg/L Cr（VI）处理之间的差异表达基因，在 Pisolithus sp.1 LS-2017 中，氰基氨基酸代谢、I 型糖尿病代谢、氮代谢和β-丙氨酸代谢途径显著富集（p<0.05）。两个硝酸盐还原酶家族基因（nidD、niiA）通过调节 Cr（VI）还原为 Pisolithus sp.1 LS-2017 提供 Cr（VI）耐受性。此外，nidD、niiA 产生的 NO 调节的反硝化作用可以减轻 Cr（VI）诱导的氧化应激。在 Pisolithus sp.2 LS-2017 中，alcC、aldA 和 lcf2 基因可能通过保护 SH 基团和增加次生代谢、分别将解毒醛还原为羧酸和产生 LCPUFAs 来减轻 Cr（VI）诱导的氧化应激；T 基因通过色素沉着和孢子中黑色素的稳定性调节 Cr（VI）诱导的伤口愈合；MKP2 基因加速 Cr（VI）诱导的细胞死亡，gpmA 基因调节 Cr（VI）诱导的能量紧急情况。
