College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China; Key Laboratory of Integrated Management of Crop Diseases and Pests (Nanjing Agricultural University), Ministry of Education, China.
School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK.
Pestic Biochem Physiol. 2018 Apr;146:25-32. doi: 10.1016/j.pestbp.2018.02.005. Epub 2018 Feb 16.
We previously reported that the mechanism of quinclorac resistance in Echinochloa crus-galli var. zelayensis may be closely related to ethylene biosynthesis and the detoxification of cyanide. Differences in EcCAS gene sequences and expression levels may result in higher capacity to detoxify cyanide in resistant biotypes, which may avoid cyanide accumulation and avoid more ethylene and cyanide production and then avoid damage. In the present study, we focused on the mechanism of resistance related to ethylene biosynthesis in E. crus-galli var. zelayensis. The fresh weight of susceptible and moderately resistant biotypes were significantly reduced after treatment with quinclorac. However, AOA, an ethylene biosynthesis inhibitor, reduced the impact of quinclorac. On pretreatment with AOA, ethylene production was significantly reduced in the three biotypes. The highly resistant biotype produced less ethylene compared to the other two biotypes. Three ACS and seven ACO genes, which are the key genes in ethylene biosynthesis, were obtained. The expression levels of EcACS-like, EcACS7, and EcACO1 varied in the three biotypes upon treatment with quinclorac, which could be manipulated by AOA. In summary, it is inferred that the expression of EcACS-like, EcACS7, and EcACO1 can be stimulated to varying extent after quinclorac treatment in three E. crus-galli var. zelayensis biotypes, which consequently results in varying levels of ethylene production. Lower expression of these three genes results in more resistance to quinclorac, which may also be related to quinclorac resistance in E. crus-galli var. zelayensis.
我们之前报道过，稗草泽莠 var. zelayensis 对氯喹酸的抗性机制可能与乙烯生物合成和氰化物解毒密切相关。EcCAS 基因序列和表达水平的差异可能导致抗性生物型具有更高的氰化物解毒能力，从而避免氰化物积累，避免更多的乙烯和氰化物产生，进而避免损伤。在本研究中，我们专注于稗草泽莠 var. zelayensis 中与乙烯生物合成相关的抗性机制。敏感和中度抗性生物型在氯喹酸处理后鲜重明显下降，但乙烯生物合成抑制剂 AOA 减轻了氯喹酸的影响。在 AOA 预处理后，三种生物型的乙烯生成量均显著降低。高抗性生物型产生的乙烯量比其他两种生物型少。获得了三个 ACS 和七个 ACO 基因，它们是乙烯生物合成的关键基因。在三种生物型中，EcACS-like、EcACS7 和 EcACO1 的表达水平在受到氯喹酸处理后发生了变化，这可以通过 AOA 来调控。综上所述，推断在三种稗草泽莠 var. zelayensis 生物型中，氯喹酸处理后 EcACS-like、EcACS7 和 EcACO1 的表达可以被不同程度地刺激，从而导致不同水平的乙烯生成。这三个基因表达水平越低，对氯喹酸的抗性越强，这可能也与稗草泽莠 var. zelayensis 对氯喹酸的抗性有关。
