Roles of xanthophylls and exogenous ABA in protection against NaCl-induced photodamage in rice (Oryza sativa L) and cabbage (Brassica campestris).
Roles of xanthophylls and exogenous ABA in protection against NaCl-induced photodamage in rice (Oryza sativa L) and cabbage (Brassica campestris).
复制标题
DOI：
10.1093/jxb/err170
复制
发表时间：
2011-08
影响因子：
6.9
通讯作者：
Su-Qin Zhu;Ming-Wei Chen;B. Ji;D. Jiao;Jian-sheng Liang
中科院分区：
文献类型：
--
作者：
Su-Qin Zhu;Ming-Wei Chen;B. Ji;D. Jiao;Jian-sheng Liang
以水稻和甘蓝为试材，研究了盐胁迫下ABA胁迫和非ABA胁迫下水稻和甘蓝叶片PSⅡ光化学实际效率、非光化学猝灭(NPQ)、叶黄素含量和脱环氧化动力学的变化。与耐盐甘蓝相比，盐胁迫下敏感植株的PSⅡ实际光化学效率(ФPS II)的下降幅度更大，PS II的还原状态更高，NPQ略有增加，而外源ABA的供应缓解了PS II实际效率(ФPS II)的下降，降低了PS II的还原状态，并导致了较高的NPQ容量。结果表明，甘蓝的光合作用电子传递活性、能量耗散能力和过剩光积累均高于水稻，且ABA处理的叶片比未处理的叶片具有更高的光合电子传递活性和更高的能量耗散能力和更低的积累量。ABA对甘蓝的影响大于对水稻的影响。外源ABA通过改变叶黄素循环的脱环氧化动力学，增加了叶黄素循环池的大小，促进了叶黄素循环组分的脱环氧化，提高了NPQ水平。光损伤的保护似乎是通过外源ABA和叶黄素循环介导的NPQ的协同作用来实现的。这种不同的光保护机制可能是提高盐胁迫下的光损伤耐受性所必需的。
Changes in actual efficiency of PS II photochemistry, non-photochemical quenching (NPQ), content of xanthophylls and kinetics of de-epoxidation were studied in ABA-fed and non-ABA-fed leaves of rice and cabbage under NaCl stress. Salt stress induced more progressive decrease in actual efficiency of PS II photochemistry (ФPS II), higher reduction state of PS II, and a small significant increase in NPQ in NaCl-sensitive rice plants as compared with NaCl-tolerant cabbage plants, whereas exogenously supplied ABA alleviated the decrease in actual efficiency of PS II photochemistry (ФPS II), induced a lower reduction state of PS II, and caused higher capacity of NPQ in ABA-fed plants than in non-ABA-fed plants. As a result, there were higher activities of photosynthetic electron transport, higher capacity of energy dissipation, and lower cumulation of excess light in cabbage than in rice plants, and in ABA-fed leaves than in non-ABA-fed leaves. The effect of ABA was more efficient in cabbage than in rice plants. Addition of exogenous ABA resulted in enhancement of the size of the xanthophyll cycle pool, promotion of de-epoxidation of the xanthophyll cycle components, and a rise in the level of NPQ by altering the kinetics of de-epoxidation of the xanthophyll cycle. Protection from photodamage appears to be achieved by coordinated contributions by exogenous ABA and xanthophyll cycle-mediated NPQ. This variety of photoprotective mechanisms may be essential for conferring photodamage tolerance under NaCl stress.