Weeds prevent the growth of the lentil crop, which significantly reduces yield. Imazethapyr (IM), a post-emergence herbicide, primarily inhibited acetolactate synthase activity by reducing branched-chain amino acid contents which had an impact on plant growth. IM application has a secondary impact of increasing oxidative stress due to ALS inhibition. The objective of the present study was to elucidate the role of antioxidant defence mechanisms in mitigating oxidative stress induced by IM treatment and weed interference in IM-tolerant (LL1397 & LL1612) and susceptible (FLIP2004-7 L & PL07) lentil genotypes that were grown under control, weedy check, and IM-treated conditions. Lower H2O2 and MDA content in tolerant genotypes after IM spray were due to increased NOX (NADPH oxidase), SOD (superoxide dismutase), CAT (catalase), peroxidase (POX), GR (glutathione reductase), APX (ascorbate peroxidase), MDHAR (monodehydroascorbate reductase) and DHAR (dehydroascorbate reductase) along with higher ascorbate (AsA) and lower DHA (dehydroascorbate) content, helped plants recover from herbicide stress. However, in susceptible genotypes, higher H2O2 and MDA contents due to reduced CAT, APX, MDHAR, DHAR and NOX activities led to loss of membrane integrity by lipid peroxidation that adversely affected the plant growth. Increased SOD, GR, MDHAR, and DHAR activities in tolerant genotypes under weedy check treatment tried to cope with weed interference-induced oxidative stress, but a lower magnitude of increase in enzyme activities and decreased H2O2-detoxifying enzyme activities led to incomplete detoxification of ROS, which affected plant development. This is the first in-depth investigation of the IM tolerance mechanism in lentil. The identified tolerance mechanism during herbicide stress and weed interference in lentil will be useful in integrated herbicide weed management.

中文翻译：

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Imazethapyr 和杂草干扰诱导的氧化应激改变了扁豆抗氧化防御系统的动力学 （Lens culinaris Medik.）


杂草会阻止扁豆作物的生长，从而显着降低产量。Imazethapyr （IM） 是一种苗后除草剂，主要通过降低对植物生长有影响的支链氨基酸含量来抑制乙酰乳酸合酶活性。IM 应用具有由于 ALS 抑制而增加氧化应激的次要影响。本研究的目的是阐明抗氧化防御机制在缓解IM处理诱导的氧化应激和杂草干扰中的作用，这些小扁豆基因型是在受控、杂草检查和IM处理条件下生长的IM耐受（LL1397 & LL1612）和敏感的（FLIP2004-7 L & PL07）。IM 喷雾后耐受基因型中 H2O2 和 MDA 含量较低是由于 NOX （NADPH 氧化酶）、SOD （超氧化物歧化酶）、CAT （过氧化氢酶）、过氧化物酶 （POX）、GR （谷胱甘肽还原酶）、APX （抗坏血酸过氧化物酶）、MDHAR （单脱氢抗坏血酸还原酶） 和 DHAR （脱氢抗坏血酸还原酶） 以及较高的抗坏血酸 （AsA） 和较低的 DHA（脱氢抗坏血酸）含量，有助于植物从除草剂胁迫中恢复。然而，在易感基因型中，由于 CAT、APX、MDHAR、DHAR 和 NOX 活性降低，较高的 H2O2 和 MDA 含量导致脂质过氧化导致膜完整性丧失，从而对植物生长产生不利影响。在杂草检查处理下，耐受基因型中 SOD、GR、MDHAR 和 DHAR 活性的增加试图应对杂草干扰诱导的氧化应激，但酶活性增加的幅度较低和 H2O2 解毒酶活性降低导致 ROS 解毒不完全，从而影响植物发育。这是对扁豆中 IM 耐受性机制的首次深入研究。 在除草剂胁迫和扁豆杂草干扰期间确定的耐受性机制将有助于除草剂杂草的综合管理。