Abscisic acid-induced hydrogen peroxide is required for anthocyanin accumulation in leaves of rice seedlings.
The role of hydrogen peroxide (H(2)O(2)) in abscisic acid (ABA)-induced anthocyanin accumulation in detached and intact leaves of rice seedlings was investigated. Treatment with ABA resulted in an accumulation of anthocyanins in detached rice leaves. Dimethylthiourea, a chemical trap for H(2)O(2), was observed to be effective in inhibiting ABA-induced accumulation of anthocyanins. Inhibitors of NADPH oxidase (diphenyleneiodonium chloride and imidazole), phosphatidylinositol 3-kinase (wortmannin and LY 294002), and a donor of nitric oxide (N-tert-butyl-alpha-phenylnitrone), which have previously been shown to prevent ABA-induced H(2)O(2) accumulation in detached rice leaves, inhibited ABA-induced anthocyanin increase. Exogenous application of H(2)O(2), however, was found to increase the anthocyanin content of detached rice leaves. In terms of H(2)O(2) accumulation, intact (attached) leaves of rice seedlings of cultivar Taichung Native 1 (TN1) are ABA sensitive and those of cultivar Tainung 67 (TNG67) are ABA insensitive. Upon treatment with ABA, H(2)O(2) and anthocyanins accumulated in leaves of TN1 seedlings but not in leaves of TNG67. Our results, obtained from detached and intact leaves of rice seedlings, suggest that H(2)O(2) is involved in ABA-induced anthocyanin accumulation in this species.
Hung
Kuo Tung
KT
Department of Agronomy, National Taiwan University, Taipei, Taiwan, Republic of China.
Cheng
Deng Guo
DG
Hsu
Yi Ting
YT
Kao
Ching Huei
CH
D000040:Abscisic Acid / Q000494:pharmacology*; D000872:Anthocyanins / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism*; D008027:Light; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors; D020030:Nitric Oxide Donors / Q000494:pharmacology; D012275:Oryza / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D000081082:Phosphoinositide-3 Kinase Inhibitors; D018515:Plant Leaves / Q000378:metabolism*; D036226:Seedlings / Q000502:physiology; D013890:Thiourea / Q000031:analogs & derivatives
D000872:Anthocyanins; D020030:Nitric Oxide Donors; D000081082:Phosphoinositide-3 Kinase Inhibitors; D000040:Abscisic Acid; C038983:1,3-dimethylthiourea; D006861:Hydrogen Peroxide; D019255:NADPH Oxidases; D013890:Thiourea