Circadian regulation of the responses of plants to herbicides

该学生将推进Dodd和先正达最近的合作发现，即昼夜节律振荡器调节植物对除草剂草甘膦的敏感性。根据杂草种类的不同（先正达，未发表），在黎明或黄昏喷洒草甘膦所造成的损害仅为正午喷洒草甘膦的十分之一，与生物钟相关的光感受器（光敏色素）会改变草甘膦的敏感性（Sharkhuu et al. 2014）。先正达在4-羟基苯基丙酮酸双加氧酶（HPPD）抑制剂（如mesotrione）和PSII抑制剂（如terbuthylazine）除草剂上有商业利益，我们将使用5-烯醇丙酮酰石草酸-3-磷酸合成酶（EPSPS）抑制剂草甘膦。科学里程碑是（M1）研究植物对三种除草剂敏感性的昼夜节律的性质和分子基础；（M2）开展试验，迅速确定新型除草剂制剂对植物造成的损害是否受昼夜调节；（M3）确定操纵叶绿体转录调节因子（sigma因子）是否会影响对抑制光系统II （PSII）的除草剂的敏感性。

The student will advance the recent collaborative finding of Dodd and Syngenta that the circadian oscillator regulates plant sensitivity to the herbicide glyphosate. Glyphosate sprayed at dawn or dusk reduces damage to one-tenth of that caused by spraying at midday, depending on weed species (Syngenta, unpublished), and a circadian clock-associated photoreceptor (phytochrome) alters glyphosate sensitivity (Sharkhuu et al. 2014). Syngenta has commercial interests in, and we will use, 4-hydroxyphenylpyruvate dioxygenase (HPPD) inhibitor (e.g. mesotrione) and PSII inhibitor (e.g. terbuthylazine) herbicides in addition to the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) inhibitor glyphosate. The scientific milestones are (M1) investigate the nature of and molecular basis for circadian rhythms of plant sensitivity to three herbicide types; (M2) develop tests to determine rapidly whether plant damage caused by novel herbicide formulations is circadian-regulated; (M3) determine whether manipulation of regulators of chloroplast transcription (sigma factors) affects sensitivity to herbicides that inhibit photosystem II (PSII).