林业科学2017，Vol.53Issue(3)：33-39,7.DOI:10.11707/j.1001-7488.20170304
杨树GRF1/2d负调控不定根的发生和发育
Negative Regulation of GRF1/2d on the Formation and Development of Adventitious Roots in Populus alba × P.glandulosa ‘84K’
摘要
Abstract
[Objective] Growth-regulating factors (GRFs) are plant-specific transcription factors that are involved in various developmental events,especially in root development.It is interesting to investigate the roles of GRFs in growth and development of tissues and organs,rooting in particular,in woody plants,which would not only increase our knowledge on the mechanisms of the regulation of adventitious root formation and also be useful for cutting propagation in woody plants.[Method] PtGRF1/2d gene and its promotor were isolated from Populus alba × P.glandulosa ‘84K’The overexpression vector of miR396-resistant construct 35S:mPtGRF1/2d-GFP and the promoter-testing vector of PP,GRF1/2d ∷GUS was generated.The miR396-resistant version of mPtGRF1/2d contained six silent mutations within the miR396-complementary domain of the PtGRF1/2d genomic clone,thereby increasing the number of mismatches between miR396 and mPtGRF1/2d without altering the amino acid sequence of the encoded PtGRF1/2d protein,mPtGRF1/2d overexpression transgenic poplars and PPtGRF1/2d ∷GUS transgenic poplars were obtained respectively.Expression characters in PPtGRF1/2d ∷GUS transgenic poplars and time of adventitious root appearance,the number and length of adventitious roots in overexpression transgenic poplars were analyzed.The expression of related transcript factors at early stage of adventitious root formation in overexpression transgenic poplars were analyzed by qRT-PCR.[Result] The results showed that the expression of PtGRF1/2d was mainly in the pericycle and tip of root,suggesting general involvement of PtGRF1/2d in the root development.The development of adventitious roots in mPtGRF1/2d overexpression transgenic poplars was significantly affected in comparison to the non-transgenic poplars used as controls.Overexpression of PtGRF1/2d caused not only the delayed initiation of adventitious roots but also the reduced number and length of adventitious roots,which indicates that PtGRF1/2d exhibits a negative regulation on initiation and development of adventitious root.qRT-PCR analysis indicated that the expression of 5 transcript factors previously shown involvement in adventitious root formation,including PtSCR,PtAIL9,PtBBM2,PtPLT1.2 and PtWOX11b,was down-regulated at early stage of adventitious root formation in overexpression transgenic poplars,which demonstrated that overexpression of PtGRF1/2d suppressed the expression of key factors for adventitious root formation thus resulted in the delayed formation of adventitious roots and the reduced number and length of adventitious roots,and finally influenced the growth of poplar.[Conclusion] PtGRF1/2d is a negative regulator of poplar adventitious root formation,functioning in the upstream of adventitious root formation regulation pathway,down-regulates the expression of adventitious root related factors for adventitious root formation thus suppresses the induction of the root primordium and adventitious root formation,and finally leads to the delayed adventitious roots appearance and the reduced number and length.关键词
PtGRF1/2d/银腺杨84K/过量表达/不定根/负调控Key words
PtGRF1/2 d/Populus alba × P.glandulosa ‘84K’/overexpression/adventitious root/negative regulation分类
农业科技引用本文复制引用
周厚君,魏凯莉,江成,赵岩秋,宋学勤,卢孟柱..杨树GRF1/2d负调控不定根的发生和发育[J].林业科学,2017,53(3):33-39,7.基金项目
国家自然科学基金面上项目“生长调节因子PtGRF10参与杨树次生生长调控的机理研究”(31570676). （31570676）
