Characterization of CcSTOP1; a C2H2-type transcription factor regulates Al tolerance gene in pigeonpea
Characterization of CcSTOP1; a C2H2-type transcription factor regulates Al tolerance gene in pigeonpea
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DOI：
10.1007/s00425-017-2777-6
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发表时间：
2018-01-01
期刊：
影响因子：
4.3
通讯作者：
Koyama, Hiroyuki
中科院分区：
文献类型：
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作者：
Daspute, Abhijit Arun;Kobayashi, Yuriko;Koyama, Hiroyuki
以烟草和木豆毛状根NtSTOP 1-KD为材料，分析了CcMATE 1的柠檬酸转运功能及其受CcSTOP 1调控的机制，结果表明CcMATE 1的CcSTOP 1结合序列与AtALMT 1启动子相似，为木豆耐铝分子机制的研究提供了理论依据。铝诱导的柠檬酸盐排泄与编码柠檬酸盐转运蛋白的多药和毒性化合物排除（CcMATE 1）的表达相关。CcMATE 1基因的异位表达使转基因烟草毛状根对铝的耐受性降低，同时STOP 1调控系统被敲除。这种功能获得的方法清楚地表明CcMATE 1参与铝解毒。CcMATE 1和另一个耐铝基因ALUMINUM SENSITIVE 3（CcALS 3）的表达受质子根毒性敏感基因1（CcSTOP 1）的调控，根据对CcSTOP 1被抑制的木豆毛状根的功能丧失分析。体外结合试验表明，铝响应CcMATE 1启动子包含GGNVS共识CcSTOP 1结合。GGNVS突变使木豆毛状根中CcMATE 1的铝诱导表达失活。这表明CcSTOP 1与启动子的结合对于CcMATE 1表达至关重要。CcMATE 1和AtALMT 1启动子的STOP 1结合位点均含有GGNVS和侧翼3'序列。GGNVS区域在CcMATE 1和AtALMT 1中是相同的。相比之下，对STOP 1具有结合亲和力的3'侧翼序列没有显示出相似性。在其他植物中也发现了具有类似结构的STOP 1结合位点。CcSTOP 1和CcMATE 1基因的特征将有助于木豆耐酸性土壤育种。
Al-responsive citrate-transporting CcMATE1 function and its regulation by CcSTOP1 were analyzed using NtSTOP1 -KD tobacco- and pigeonpea hairy roots, respectively, CcSTOP1 binding sequence of CcMATE1 showed similarity with AtALMT1 promoter.The molecular mechanisms of Aluminum (Al) tolerance in pigeonpea (Cajanus cajan) were characterized to provide information for molecular breeding. Al-inducible citrate excretion was associated with the expression of MULTIDRUGS AND TOXIC COMPOUNDS EXCLUSION (CcMATE1), which encodes a citrate transporter. Ectopic expression of CcMATE1-conferred Al tolerance to hairy roots of transgenic tobacco with the STOP1 regulation system knocked down. This gain-of-function approach clearly showed CcMATE1 was involved in Al detoxification. The expression of CcMATE1 and another Al-tolerance gene, ALUMINUM SENSITIVE 3 (CcALS3), was regulated by SENSITIVE TO PROTON RHIZOTOXICITY1 (CcSTOP1) according to loss-of-function analysis of pigeonpea hairy roots in which CcSTOP1 was suppressed. An in vitro binding assay showed that the Al-responsive CcMATE1 promoter contained the GGNVS consensus bound by CcSTOP1. Mutation of GGNVS inactivated the Al-inducible expression of CcMATE1 in pigeonpea hairy roots. This indicated that CcSTOP1 binding to the promoter is critical for CcMATE1 expression. The STOP1 binding sites of both the CcMATE1 and AtALMT1 promoters contained GGNVS and a flanking 3' sequence. The GGNVS region was identical in both CcMATE1 and AtALMT1. By contrast, the 3' flanking sequence with binding affinity to STOP1 did not show similarity. Putative STOP1 binding sites with similar structures were also found in Al-inducible MATE and ALMT1 promoters in other plant species. The characterized Al-responsive CcSTOP1 and CcMATE1 genes will help in pigeonpea breeding in acid soil tolerance.