Nitric oxide protects sour pummelo (Citrus grandis) seedlings against aluminum-induced inhibition of growth and photosynthesis

作者：Yang, Lin-Tong; Qi, Yi-Ping; Chen, Li-Song^*; Sang, Wen; Lin, Xiu-Ji; Wu, Ya-Lian; Yang, Chun-Jiao

来源：Environmental and Experimental Botany, 2012, 82: 1-13.

DOI：10.1016/j.envexpbot.2012.03.004

• Aluminum
• Antioxidant system
• Chlorophyll a fluorescence (OJIP) transient
• Sodium nitroprusside (SNP)

Limited data are available on the amelioration of nitric oxide (NO) on aluminum (Al)-toxicity. Sour pummelo(Citrus grandis) seedlings were irrigated for 18 weeks with nutrient solution containing 0 and 1.2 mM AlCl3.6H(2)O x 0 and 10 mu M sodium nitroprusside (SNP, an NO donor). Under Al stress, SNP increased root phosphorus (P) and Al, but decreased shoot Al. Al decreased photosynthesis, maximum quantum yield of primary photochemistry (F-v/F-m) and total performance index (PItot,sbs), but increased inactivation of oxygen-evolving complex (OEC), K-band and relative variable fluorescence at I-steps (V-I). SNP alleviated Al-induced changes for all these parameters. SNP stimulated Al-induced secretion of malate and citrate by excised roots from Al-treated seedlings, while Al did not increase their contents in roots. Antioxidant system in leaves and roots was up- and down-regulated by Al, respectively. SNP prevented Al-induced accumulation of malondialdehyde (MDA) in roots and leaves. In conclusion, SNP alleviates Al-induced inhibition of growth and impairment of the whole photosynthetic electron transport chain. This occurs through increasing AI-immobilization and P level in roots and Al-induced secretion of malate and citrate from roots, and decreasing Al accumulation in shoots. Thus, the decrease of photosynthesis is prevented. Increased P level and Al-immobilization in roots through SNP may be effected through enhanced secretion of malate and citrate.

• 出版日期2012-10
• 单位福建农林大学