Paporisch Amit, Rubin Baruch
R. H. Smith Institute of Plant Science & Genetics in Agriculture, Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot 76100, Israel.
R. H. Smith Institute of Plant Science & Genetics in Agriculture, Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot 76100, Israel.
Pestic Biochem Physiol. 2017 May;138:22-28. doi: 10.1016/j.pestbp.2017.02.002. Epub 2017 Feb 16.
Three sweet corn genotypes, two inbred lines (IBER001 and IBER002) and their hybrid (ER00X), differ in their phenotypic responses to several P450-metabolized herbicides, used in sweet corn, namely, foramsulfuron, iodosulfuron, rimsulfuron and tembotrione. Foramsulfuron is a sulfonylurea herbicide commonly formulated with the safener isoxadifen that is used for selective post-emergence weed control in corn. Our goal was to elucidate the mechanism of these genotypes' responses to foramsulfuron and safener isoxadifen and examine the heritability of those responses. IBER001 was sensitive to foramsulfuron+isoxadifen, with an ED of 3.6gaiha, while IBER002 and ER00X were tolerant with ED values of 808 and 700gaiha, respectively. ALS enzyme extracted from each of the different genotypes was equally sensitive to foramsulfuron. Pre-treatment with malathion, a known cytochrome P450 inhibitor, increased foramsulfuron injury in IBER002 and ER00X, but had no effect on those lines when isoxadifen was applied with the herbicide. Foramsulfuron-treated IBER001 was severely injured regardless of the presence of malathion and/or isoxadifen. Pre-treatment with malathion similarly increased the phytotoxicity of iodosulfuron+safener (mefenpyr) and rimsulfuron to the tolerant genotypes, but did not increase the level of injury caused by the tembotrione+isoxadifen treatment. Segregation of F2 and backcross progenies according to their responses to foramsulfuron+isoxadifen revealed a pattern of inheritance typical of a trait controlled by a single gene inheritance, with a recessive allele conferring sensitivity. Our results support the hypothesis that foramsulfuron selectivity is associated with P450 metabolism and that isoxadifen positively affects P450 activity. The sensitive genotype that does not respond to isoxadifen is presumably homozygous for a deficient or non-functioning P450 gene.
三种甜玉米基因型，即两个自交系（IBER001和IBER002）及其杂交种（ER00X），对甜玉米中使用的几种由细胞色素P450代谢的除草剂，即甲酰胺磺隆、碘磺隆、烟嘧磺隆和苯唑草酮，表现出不同的表型反应。甲酰胺磺隆是一种磺酰脲类除草剂，通常与安全剂异恶草酮复配，用于玉米苗后选择性防除杂草。我们的目标是阐明这些基因型对甲酰胺磺隆和安全剂异恶草酮的反应机制，并研究这些反应的遗传力。IBER001对甲酰胺磺隆+异恶草酮敏感，有效剂量（ED）为3.6克活性成分/公顷，而IBER002和ER00X具有耐受性，有效剂量分别为808和700克活性成分/公顷。从每种不同基因型中提取的乙酰乳酸合成酶（ALS）对甲酰胺磺隆的敏感性相同。用已知的细胞色素P450抑制剂马拉硫磷预处理，增加了IBER002和ER00X中甲酰胺磺隆的伤害，但当异恶草酮与除草剂一起施用时，对这些品系没有影响。无论是否存在马拉硫磷和/或异恶草酮，用甲酰胺磺隆处理的IBER001都会受到严重伤害。用马拉硫磷预处理同样增加了碘磺隆+安全剂（苯酯草醚）和烟嘧磺隆对耐受性基因型的植物毒性，但没有增加苯唑草酮+异恶草酮处理造成的伤害水平。根据F2和回交后代对甲酰胺磺隆+异恶草酮的反应进行分离，揭示了一种由单基因遗传控制的性状的典型遗传模式，隐性等位基因赋予敏感性。我们的结果支持以下假设：甲酰胺磺隆的选择性与细胞色素P450代谢有关，异恶草酮对细胞色素P450活性有正向影响。对异恶草酮无反应的敏感基因型可能是P450基因缺陷或无功能的纯合子。
