Tuber development and propagation are inhibited by GA3 effects on the DELLA-dependent pathway in purple nutsedge (Cyperus rotundus)

Abstract Purple nutsedge ( Cyperus rotundus L.) is a globally distributed noxious weed that poses a significant challenge for control due to its fast and efficient propagation through the tuber, which is the primary reproductive organ. Gibberellic acid (GA 3 ) has proven to be crucial for tuberization in tuberous plants. Therefore, understanding the relationship between GA 3 and tuber development and propagation of C. rotundus will provide valuable information for controlling this weed. This study shows that the GA 3 content decreases with tuber development, which corresponds to lower expression of bioactive GA 3 synthesis genes ( CrGA20ox , two CrGA3ox genes) and two upregulated GA 3 catabolism genes ( CrGA2ox genes ) , indicating that GA 3 is involved in tuber development. Simultaneously, the expression of two CrDELLA genes and CrGID1 declines with tuber growth and decreased GA 3 , and yeast two-hybrid assays confirm that the GA 3 signaling is DELLA-dependent. Furthermore, exogenous application of GA 3 markedly reduces the number and the width of tubers and represses the growth of the tuber chain, further confirming the negative impact that GA 3 has on tuber development and propagation. Taken together, these results demonstrate that GA 3 is involved in tuber development and regulated by the DELLA-dependent pathway in C. rotundus and plays a negative role in tuber development and propagation.