Is the protection of photosynthesis related to the mechanism of quinclorac resistance in Echinochloa crus-galli var. zelayensis?
Is the protection of photosynthesis related to the mechanism of quinclorac resistance in Echinochloa crus-galli var. zelayensis?
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DOI：
10.1016/j.gene.2018.10.022
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发表时间：
2019-01-30
期刊：
影响因子：
3.5
通讯作者：
Dong, Liyao
中科院分区：
文献类型：
--
作者：
Gao, Yuan;Pan, Xukun;Dong, Liyao
稗草zelayensis、E. crus-galli（L.）博夫已进化出对二氯喹啉酸的抗药性，但抗药性机制仍不清楚。二氯喹啉酸处理使敏感的E.克鲁斯加利湾zelayensis在72 h内。然后对敏感和抗性的E.克鲁斯加利湾结果表明，敏感型中差异表达基因（1115个，上调548个，下调567个）多于抗性型（901个，上调373个，下调528个）。筛选出34个与光合作用相关的候选基因，其中29个基因受二氯喹啉酸的影响在敏感型中大于抗性型。qPCR验证涉及更多的采样时间点显示，在连续处理50 μ mol/L的二氯喹啉酸，34个光合相关基因的表达水平显着下降2-1000倍，在12小时内的敏感生物型。在二氯喹啉酸处理后6小时表达显著或轻微下降后，12小时后观察到21个基因的表达水平恢复，另外13个基因的表达水平在抗性生物型中保持不变。据推测，光合作用相关基因表达的持续急剧下降是敏感生物型死亡的主要原因。此外，据推断，在抗性生物型中可能存在一种调节机制，允许这些基因的表达显著不受影响或迅速恢复，从而防止二氯喹啉酸对植物造成严重损害。
Echinochloa crus-galli var. zelayensis, a variety of E. crus-galli (L.) Beauv. has evolved resistance to quinclorac, but the mechanism of resistance remains unclear. Treatments with quinclorac, cause rapid leaf chlorosis, continuous decrease in the chlorophyll content to about 0.4 times, and rapid decline in biomass by about 20% in sensitive E. crus-galli var. zelayensis within 72 h. Then transcriptome sequencing for quinclorac-sensitive and-resistant E. crus-galli var. zelayensis biotypes was performed, and more differentially expressed genes (DEGs) were observed in the sensitive biotype (1115 DEGs, including 548 up-regulated and 567 down-regulated) than that in the resistant biotype (901 DEGs, including 373 up-regulated and 528 down-regulated). Thirty-four photosynthesis related candidate genes were screened, in which twenty-nine genes were more affected by quinclorac in the sensitive biotype than that in the resistant biotype. The qPCR verification involving more sampling time-points revealed that on continuous treatment with 50 mu mol/L quinclorac, expression levels of 34 photosynthesis-related genes dropped significantly by 2-1000 times within 12 h in the sensitive biotype. Following significant or marginal decline in expression at 6 h after quinclorac treatment, recovery of the expression levels of 21 genes was observed after 12 h and the expression levels of another 13 genes remained unaltered in the resistant biotype. It is hypothesized that the sustained sharp decrease in the expression of photosynthesis-related genes is a major cause of death in the sensitive biotype. Further, it is inferred that there may be a regulatory mechanism in the resistant biotype that allowed the expression of these genes to be significantly unaffected or to rapidly recover, in turn preventing severe damage to the plants caused by quinclorac.