干旱对欧美杨气孔发育的影响  

Drought induces alterations in stomatal development in Populus deltoides × P. nigra

作　　者：王丛鹏[1] 贾伏丽 刘沙[1] 刘超[1] 夏新莉[1] 尹伟伦[1] 

机构地区：[1]北京林业大学林木育种国家工程实验室

出　　处：《北京林业大学学报》2016年第6期28-34,共7页Journal of Beijing Forestry University

基　　金："十二五"国家科技支撑计划项目(2015BAD07B01);国家自然科学基金项目(31270656)

摘　　要：为了探究干旱对木本植物气孔发育的影响,本文挑选了5个欧美杨无性系NE-19、R270、107、109和111,进行了14 d的自然干旱处理及7 d的复水处理。结果发现:NE-19、R270与107的光合速率在复水后第5天恢复至处理前水平,气孔导度在第3天恢复至处理前水平,而109与111在复水处理期间光合与气孔导度恢复缓慢。测量各无性系复水后的生长速率,与对照组相比由快到慢依次为NE-19(64.96%)、R270(55.73%)、107(49.87%)、109(35.08%)、111(23.62%)。综合光合、气孔导度与生长的数据,5个无性系耐旱性由强至弱的排序为NE-19、R270、107、109、111。统计5个无性系在处理期间幼叶气孔指数的变化,发现各无性系在干旱期间气孔发育速度均下降。其中NE-19与R270下降最多,分别为30.75%和29.24%,说明耐旱性好的无性系,更善于调节幼叶中的气孔发育来适应外界的水分变化。通过荧光定量PCR检测与气孔发育相关基因ERECTA、EPF1、EPFL9、FAMA、SDD1在处理期间处理组与对照组的表达量差异,发现在干旱期间对气孔发育正调控的EPFL9与FAMA表达量下降,而负调控气孔发育的ERECTA与EPF1表达量上调,在NE-19与R270中的变化幅度尤为明显,而SDD1在整个处理期间表达量没有十分明显的变化。研究发现欧美杨在干旱中可通过调节气孔发育相关基因ERECTA、EPF1、EPFL9和FAMA的表达来抑制幼叶气孔发育,从而减少叶片水分散失以抵御干旱胁迫。To explore the effect of drought to stomatal development in woody plants, five Populus deltoides x P. nigra clones, i. e., R270 （ P. deltoides x P. nigra）, NE-19 [ P. nigra × （ P. deltoides x P. nigra） ], 107 （P. x euramericana ＇74/76＇）, 109 （P. deltoides x P. alba ＇Mincio＇） and 111 （P. deltoides × euramericana ＇ Bellotto＇ ） were selected to undergo 14 days of drought and 7 days of re- watering treatment. The results showed that photosynthesis of NE-19, R270 and 107 returned to the normal level at the fifth day after re-watered, with stomatal conductance back to normal level after 3 days. However, 109 and 111 recovered slowly. As for the growth rate after re-watered, the order from high to low was NE-19 （64.96%）, R270 （55.73%）, 107（49.87%）, 109（35.08%）, and 111 （23.62%）. According the results of photosynthesis, stomatal conductance and growth rate, the drought tolerance was ranked as NE-19 〉 R270 〉 107 〉 109 〉 111. For all five clones, the stomatal development slowed down when subjected to the drought, indicated by the stomatal index （SI） in young leaves. The SI of NE-19 and R270 had the most remarkable change during the drought, being 30.75% and 29.24% , respectively. The clones with better drought tolerance may be more positively responsive to ambient water content change through stomatal development. Using qRT-PCR we tested the difference of transcript abundance of five genes associated with stomatal development between control and drought treatment groups. EPFL9 and FAMA, which positively control stomatal development, were downregulated during drought, but ERECTA and EPF1 which negatively regulate the process were upregulated during drought, and SDD1 had no change during the whole treatment. Our findings highlight that poplar inhibits stomatal development through adjusting expression of ERECTA, EPF1, EPFL9 and FAMA in immature leaves to reduce water loss so as to withstand drought stress.

关 键 词：欧美杨 气孔发育 干旱 基因调节 

分 类 号：S718.47[农业科学—林学] S792.119