Regulation of DTA-6 by Abscission Cellulase and GmAC Gene Expression in Flowers and Pods of Soybean

Abstract

It is effective to regulate abscission of soybean flowers and pods by spraying plant growth regulators (PGRs). This study was carried out to determine the effect of DTA-6 on abscission cellulase (AC) activity, abscission cellulase gene (GmAC) expressive, abscission of flowers and pods, and yield in soybean. DTA-6 was foliage sprayed at R1 stage on three varieties of Suinong 28, Kenfeng 16, and Hefeng 50 in 2012 and 2013. The results demonstrated that DTA-6 treatment inhibited GmAC gene expression in abscission zone of flower and pod, with the maximum reduction of 51% among three varieties compared with the control. The abscission cellulase activity was periodically decreased by DTA-6, with different decrements among soybean culti- vars. DTA-6 significantly decreased (P<0.05) abscission rate of soybean flowers and pods, and significantly increased yield (P<0.05). The relative expression of abscission cellulase gene (GmAC) in abscission zone of flowers-pods was decreased and the AC activity was regulated by DTA-6, resulting in reduced abscission rate of soybean flowers and pods and promoted yield.