【正文】 它控制擬南芥RD29B基因在應答脫落酸時的表達。這些AREB/ABF蛋白質需要一個脫落酸介導信號的激活。這種現(xiàn)象很可能是由于脫落酸依賴型的AREB/ABF蛋白質的磷酸化造成的。最近，轉基因植物表達中有一個AREB1基因的磷酸化形式，它的多點突變顯示了許多無外源脫落酸應用的脫落酸應答基因的誘導。干旱誘導RD22基因的誘導是被脫落酸和脫落酸依賴型的表達所需要的蛋白質的生物合成介導的。這些MYC和MYB蛋白質在內源性脫落酸積累的情況下被合成，它們的作用可以在稍后的應激反應階段中確定。AtMYC2 和AtMYB2基因的過度表達，使轉基因植物中不僅產生了脫落酸過敏表型，也提高了轉基因植物的滲透脅迫耐受性。這種RD26NAC轉錄因子的表達可被干旱、高鹽、脫落酸和茉莉酸處理誘導。一個RD26基因過度表達的轉基因植物對脫落酸很敏感。據(jù)觀察，在RD26基因過度表達的轉基因植物和具有RD26阻遏基因的植物中脫落酸和脅迫誘導基因被上調。這表明在干旱和受傷的應激反應中，RD26在調解脫落酸信號和茉莉信號的竄擾中起到了重要的作用。結論基因芯片的轉錄分析是在發(fā)現(xiàn)應激反應基因的過程中使用的強大的工具，利用該工具不僅在擬南芥也在各種農作物和樹木中發(fā)現(xiàn)了應激反應基因。此外，在轉基因植物中基因的的過度表達對脅迫誘導基因的功能分析和提高轉基因植物的脅迫耐受性都是非常有益的。參考文獻[1] Abe H, Urao T, Ito T, Seki M, Shinozaki K, YamaguchiShinozaki K. 2003. Arabidopsis AtMYC2 (bHLH) and AtMYB2(MYB) function as transcriptional activators in abscisic acid signaling. The Plant Cell 15, 63–78.[2] Abe H, YamaguchiShinozaki K, Urao T, Iwasaki T, HosokawaD, Shinozaki K. 1997. Role of Arabidopsis MYC andMYB homologs in drought and abscisic acidregulated gene expression. The Plant Cell 9, 1859–1868.[3]Bartels D, Sunkars R. 2005. Drought and salt tolerance in Reviews in Plant Science 24, 23–58.[3] Choi H, Hong JH, Ha J, Kang JY, Kim SY. 2000. ABFs, a familyof ABAresponsive elements binding factors. Journal of BiologicalChemistry 275, 1723–1730.[4] Dubouzet JG, Sakuma Y, Ito Y, Kasuga M, Dubouzet EG, MiuraS, Seki M, Shinozaki K, YamaguchiShinozaki K. genes in rice, Oryza sativa L, encode transcription activatorsthat function in drought, highsalt and coldresponsive gene expression. The Plant Journal 33, 751–763.[5] Fowler SG, Thomashow MF. 2002. Arabidopsis transcriptomeprofiling indicates that multiple regulatory pathways are activatedduring cold acclimation in addition to the CBF cold responsepathway. The Plant Cell 14, 1675–1690.[6] Fujita M, Fujita Y, Maruyama K, Seki M, Hiratsu K, OhmeTakagi M, Tran LSP, YamaguchiShinozaki K, Shinozaki . A dehydrationinduced NAC protein, RD26, is involved in anovel ABAdependent stresssignaling pathway. The Plant Journal39, 863–876.[7] Fujita Y, Fujita M, Satoh R, Maruyama K, Parvez MM, Seki M,Hiratsu K, OhmeTakagi M, Shinozaki K, YamaguchiShinozakiK. 2005. AREB1 is a transcription activator of novel ABREdependentABA signaling that enhances drought stress tolerancein Arabidopsis. The Plant Cell 17, 3470–3488.[8] Furihata T, Maruyama K, Fujita Y, Umezawa T, Yoshida R,Shinozaki K,YamaguchiShinozaki K. 2006. Abscisic aciddependentmultisite phosphorylation regulates the activity of a transcriptionactivator AREB1. Proceedings of the National Academyof Sciences, USA 103, 1988–1993.[9] Ito Y, Katsura K, Maruyama K, Taji T, Kobayashi M, Seki M,Shinozaki K, YamaguchiShinozaki K. 2006. Functional analysisof rice DREB1/CBFtype transcription factors involved in coldresponsivegene expression in transgenic rice. Plant and Cell Physiology 47, 141–153.[10] Iuchi S, Kobayshi M, Taji T, Naramoto M, Seki M, Kato T,Tabata S, Kakubari Y, YamaguchiShinozaki K, Shinozaki . Regulation of drought tolerance by gene manipulation of 9cisepoxycarotenoid, a key enzyme in abscisic acid biosynthesisin Arabidopsis. The Plant Journal 27, 325–333.[11] JagloOttosen KR, Gilmour SJ, Zarka DG, Schabenberger O,Thomashow MF. 1998. Arabidopsis CBF1 overexpression inducescoe genes and enhances freezing tolerance. Science 280, 104–106.[12] Kang JY, Choi HI, Im MY, Kim SY. 2002. Arabidopsis basicleucine zipper proteins that mediate stressresponsive abscisic acidsignaling. The Plant Cell 14, 343–357.[13] Kasuga M, Liu Q, Miura S, YamaguchiShinozaki K, Shinozaki . Improving plant drought, salt, and freezing tolerance by gene