Abstract:
The role of nitric oxide (NO) in naphthaleneacetic acid (NAA)-induced adventitious roots formation in mung bean (Phaseolus radiatus L.) hypocotyl cuttings was studied. The results showed that, compared with the control, both NO donor sodium nitroprusside (SNP) and NAA significantly raised number, fresh and dry weight of adventitious roots. The treatment with complex of NAA and SNP resulted in significant increase in adventitious roots number compared with the treatment using SNP or NAA alone. Carboxy-2-phenyl-4,4,5,5-tetramethylimidazoline (c-PTIO), a NO specific scavenger, effectively inhibited NAA-induced adventitious root formation, and the optimal concentration was 200 μmol/L. Furthermore, inhibitor of nitric oxide synthase (NOS), N'-nitro-L-arginine methyl ester (L-NAME) partly inhibited the effect from NAA, the optimal concentration was 30mmol/L. Detection of endogenous NO showed that the level of NO was obviously promoted by NAA, however, innibitd by c-PTIO and L-NAME. All results mentioned above indicated that NO plays a key role in NAA-induced adventitious roots formation, and NOS is involved in the generation of NO in this process.
