title: Drought-induced proline accumulation is uninvolved with increased nitric oxide, which alleviates drought stress by decreasing transpiration in rice.
abstract: Accumulation of proline is trusted to be an adaptive response of plants against drought stress, and exogenous application of nitric oxide (NO) enhances proline accumulation in Cu-treated algae. In order to investigate whether NO works as a necessary signaling molecule in drought-induced proline accumulation in rice leaves, effects of drought stress on endogenous NO content and proline accumulation were studied in rice leaves, using sodium nitroprusside (SNP, a NO donor) and 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO, a NO scavenger). The results showed that drought treatment increased both endogenous NO and proline contents in rice leaves, while foliar spray of various concentrations of SNP failed to induce proline accumulation in the leaves of well-watered rice and foliar spray of cPTIO failed to inhibit proline accumulation in the leaves of drought-stressed rice. These results indicate that increase of endogenous NO is dispensable for proline accumulation in the leaves of rice under drought stress. Further studies indicate that exogenous application of NO alleviates drought-induced water loss and ion leakage by decreasing transpiration rate of rice leaves.
authors.affiliation: State Key Laboratory of Rice Biology, China National Rice Research Institute, 359 Tiyuchang Road, Hangzhou, 310006, People's Republic of China. jiexiong@zju.edu.cn
authors.forename: Jie
authors.initials: J
authors.lastname: Xiong
authors.forename: Long
authors.initials: L
authors.lastname: Zhang
authors.forename: Guanfu
authors.initials: G
authors.lastname: Fu
authors.forename: Yongjie
authors.initials: Y
authors.lastname: Yang
authors.forename: Cheng
authors.initials: C
authors.lastname: Zhu
authors.forename: Longxing
authors.initials: L
authors.lastname: Tao
mesh_terms: D001565:Benzoates; D055864:Droughts; D007093:Imidazoles; D007477:Ions; D009569:Nitric Oxide / Q000378:metabolism*; D009599:Nitroprusside / Q000494:pharmacology; D012275:Oryza / Q000187:drug effects / Q000502:physiology*; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D018526:Plant Transpiration / Q000187:drug effects / Q000502:physiology*; D011392:Proline / Q000378:metabolism*; D012987:Soil / Q000737:chemistry; D013312:Stress, Physiological / Q000187:drug effects; D014867:Water / Q000502:physiology
chemical_list: D001565:Benzoates; D007093:Imidazoles; D007477:Ions; D012987:Soil; D014867:Water; C079393:1,3-dihydroxy-4,4,5,5-tetramethyl-2-(4-carboxyphenyl)tetrahydroimidazole; D009599:Nitroprusside; D009569:Nitric Oxide; D011392:Proline