Programmed cell death, antioxidant response and oxidative stress in wheat flag leaves induced by chemical hybridization agent SQ-1

• Main Authors: Shu-ping WANG, Gai-sheng ZHANG, Qi-lu SONG, Ying-xin ZHANG, Ying LI, Jia-lin GUO, Zheng CHEN, Na NIU, Shou-cai MA, Jun-wei WANG
• Format: Article
• Language: English
• Published: Elsevier 2016-01-01
• Series: Journal of Integrative Agriculture
• Subjects: wheat flag leaf; chemical hybridization agent SQ-1; programmed cell death; antioxidant response; oxidative stress
• Online Access: http://www.sciencedirect.com/science/article/pii/S2095311914609771

Male sterility induced by a chemical hybridization agent (CHA) is an important tool for utilizing crop heterosis. Leaves, especially the flag leaves, as CHA initial recipients play a decisive role in inducing male sterility. To investigate effects of different treatment times of CHA-SQ-1 used, morphological, biochemical and physiological responses of wheat flag leaves were detected in this study. CHA induced programmed cell death (PCD) as shown in terminal deoxynucleotidyl transferase-mediated dUTP nick end-labelling (TUNEL) and DNA laddering analysis. In the early phase, CHA-SQ-1 trig-gered organelle changes and PCD in wheat leaves accompanied by excess production of reactive oxygen species (O2 and H2O2) and down-regulation of the activities of superoxide dismutase (SOD), catalase (CAT) and guaiacol peroxidase (POD). Meanwhile, leaf cell DNAs showed ladder-like patterns on agarose gel, indicating that CHA-SQ-1 led to the activation of the responsible endonuclease. The oxidative stress assays showed that lipid peroxidation was strongly activated and photosynthesis was obviously inhibited in SQ-1-induced leaves. However, CHA contents in wheat leaves gradually reduced along with the time CHA-SQ-1 applied. Young flags returned to an oxidative/antioxidative balance and ultimately developed into mature green leaves. These results provide explanation of the relations between PCD and anther abortion and practical application of CHA for hybrid breeding.