LeCTR1, a tomato CTR1-like gene, demonstrates ethylene signaling ability in Arabidopsis and novel expression patterns in tomato
LeCTR1, a tomato CTR1-like gene, demonstrates ethylene signaling ability in Arabidopsis and novel expression patterns in tomato
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DOI：
10.1104/pp.009415
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发表时间：
2002-11-01
期刊：
影响因子：
7.4
通讯作者：
Bouzayen, M
中科院分区：
文献类型：
--
作者：
Leclercq, J;Adams-Phillips, LC;Bouzayen, M
LeCTR 1最初是通过差异显示逆转录-聚合酶链反应筛选番茄（Lycopersicon esculentum）果实乙烯诱导基因和通过与拟南芥CTR 1 cDNA同源性分离的。LeCTR 1与拟南芥CTRL（一种作用于乙烯受体下游的基因）具有很强的核苷酸序列同源性，并显示出与丝氨酸/苏氨酸蛋白激酶Raf家族的相似性。LeCTR 1转录区从ATG到终止密码子的长度（12，000 bp）是拟南芥CTR 1（4，700 bp）的两倍多。结构分析表明，LeCTR 1和拟南芥CTR 1的内含子和外显子的数量和位置都是完全保守的。然而，LeCTR 1中的内含子要长得多。为了解决这种结构保守性是否指示相应蛋白质的功能保守性，我们在35 S启动子的指导下在拟南芥cDNA-I（组成型三重应答1）突变体中表达LeCTR 1。我们的数据清楚地表明，异位表达的LeCTR 1在拟南芥突变体cDNA-1可以恢复正常的乙烯信号。在异源表达LeCTR 1后正常乙烯敏感性的恢复也通过拟南芥突变体中不存在的恢复的葡萄糖敏感性来证实。表达研究证实了LeCTR 1在包括成熟果实在内的各种组织中的乙烯响应性，并且可能表明番茄与拟南芥中替代调节机制的进化。
LeCTR1 was initially isolated by both differential display reverse transcriptase-polymerase chain reaction screening for tomato (Lycopersicon esculentum) fruit ethylene-inducible genes and through homology with the Arabidopsis CTR1 cDNA. LeCTR1 shares strong nucleotide sequence homology with Arabidopsis CTRL a gene acting downstream of the ethylene receptor and showing similarity to the Raf family of serine/threonine protein kinases. The length of the LeCTR1 transcribed region from ATG to stop codon (12,000 bp) is more than twice that of Arabidopsis CTR1 (4,700 bp). Structural analysis reveals perfect conservation of both the number and position of introns and exons in LeCTR1 and Arabidopsis CTR1. The introns in LeCTR1 are much longer, however. To address whether this structural conservation is indicative of functional conservation of the corresponding proteins, we expressed LeCTR1 in the Arabidopsis ctrl-1 (constitutive triple response 1) mutant under the direction of the 35S promoter. Our data clearly show that ectopic expression of LeCTR1 in the Arabidopsis ctrl-1 mutant can restore normal ethylene signaling. The recovery of normal ethylene sensitivity upon heterologous expression of LeCTR1 was also confirmed by restored glucose sensitivity absent in the Arabidopsis ctrl-1 mutant. Expression studies confirm ethylene responsiveness of LeCTR1 in various tissues, including ripening fruit, and may suggest the evolution of alternate regulatory mechanisms in tomato versus Arabidopsis.