Herbicides are the major tool for controlling large populations of yield depleting weeds. However, over-reliance on herbicides has resulted in weed adaptation and herbicide resistance. In recent years, early flowering weed species related to herbicide resistance is emerging, which may cause seed loss before crop harvest, creating a new problem for non-chemical weed management. In this study, a homologue gene of AGAMOUS sub-family (referred to as PfAG5) of the MADS-box family was cloned from plants of an early flowering Polypogon fugax Nees ex Steud. population resistant to the ACCase inhibitor herbicide (clodinafop-propargyl). The PfAG5 gene was functionally characterised in Arabidopsis thaliana L. Overexpression of the PfAG5 gene in Arabidopsis resulted in early flowering, abnormal flowers (e.g. small petals), short plants and reduced seed set, compared with the wild type. The expression of the PfAG5 gene was high in leaves and flowers, but low in pods in transgenic Arabidopsis. The PfAG5 gene was expressed earlier and higher in the resistant (R) than the susceptible (S) P. fugax plants. Furthermore, one protein (FRIGIDA-like) with relevance to flowering time regulation and interacts with PfAG5 in resistant (R) P. fugax was identified by the yeast two-hybrid and pull-down assays. These results suggest that the PfAG5 gene is involved in modulating early flowering in P. fugax.

除草剂是控制大量单产枯竭杂草的主要工具。但是，对除草剂的过度依赖导致了杂草适应性和除草剂抗性。近年来，出现了与抗除草剂有关的早花杂草，这可能导致作物收获前种子流失，给非化学杂草管理带来了新问题。在这项研究中，从早期开花的Polypogon fugax Nees ex Steud的植物中克隆了MADS-box家族的AGAMOUS亚家族的同源基因（称为PfAG5）。对ACCase抑制剂除草剂（clodinafop-propargyl）有抗药性的种群。该PfAG5基因功能特征拟南芥L.与野生型相比，PfAG5基因在拟南芥中的过表达导致了早期开花，异常花朵（例如小花瓣），短植和种子结实减少。在转基因拟南芥中，PfAG5基因的表达在叶和花中高，但在豆荚中低。所述PfAG5基因在抗性（R）比易感（S）更早和更高的表达P. fugax植物。此外，一个蛋白（FRIGIDA样）与关联于开花时间调节和相互作用与PfAG5在抗性（R）P. fugax鉴定通过酵母双杂交和下拉测定法。这些结果表明PfAG5基因参与调控开花早在P. fugax。