柑橘CitERF9和CitAP2-7在不同逆境和外源激素处理下的表达

以‘资阳’香橙(Citrus junos‘Ziyang’)为试材,分别对Cit ERF9和Cit AP2-7进行了分析。结果表明:Cit ERF9基因的开放阅读框(ORF)为735 bp,含有1个外显子,可编码244个氨基酸残基的多肽。Cit AP2-7的开放阅读框为1 080 bp,具有6个外显子,可编码360个氨基酸残基。同源分析结果显示,这两个基因编码的蛋白与大豆、蓖麻、碧桃、苜蓿等植物中的同源蛋白有81%~84%的相似性。实时定量分析表明:Cit ERF9和Cit AP2-7在植株不同组织间的表达具有明显差异。在根中,Cit ERF9受各种胁迫处理诱导,而Cit AP2-7主要受ABA、Na Cl、脱水等的诱导。在叶中,各种胁迫均对Cit ERF9具有诱导作用,其模式与根中相似,而Cit AP2-7的表达则主要受ABA、ACC、Me JA、SA等激素以及低温和Na Cl的抑制。试验结果表明,Cit ERF9和Cit AP2-7参与了激素和非生物胁迫的响应过程。

Expression of Two Citrus AP2/ERF Genes Under Different Hormone and Stress Treatments

Two AP2/ERF genes，CitERF9 and CitAP2-7 were analyzed in Citrus junos‘Ziyang’. Thedata showed that CitERF9 genomic sequence contained a single exon of 735 bp long，which could encodea protein of 244 amino acid residues. In contrast，CitAP2-7 genomic sequence possessed 5 introns and its 6exons could encode a protein of 360 amino acid residues. Sequence alignment showed that CitERF9 andCitAP2-7 shared 81%–84% amino acid identities with corresponding AP2/ERF members from soybean，castor，peach and alfalfa. Real time quantitative analysis revealed that the expression of CitAP2-7 andCitERF9 in different tissues exhibited different patterns. In roots，CitERF9 was induced by all hormoneand stress treatments，whereas CitAP2-7 was mainly modulated by NaCl，ABA and dehydration. In leaves，CitERF9 was up-regulated by all treatments，similar to that in roots. But CitAP2-7 was suppressed byABA，ACC，MeJA，SA and NaCl treatments. The results suggested the involvement of both CitERF9 andCitAP2-7 in the responses of citrus to stresses and relevant hormones.