AtHVA22 gene family in Arabidopsis:: phylogenetic relationship, ABA and stress regulation, and tissue-specific expression
AtHVA22 gene family in Arabidopsis:: phylogenetic relationship, ABA and stress regulation, and tissue-specific expression
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DOI：
10.1023/a:1015593715144
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发表时间：
2002-08-01
影响因子：
5.1
通讯作者：
Ho, THD
中科院分区：
文献类型：
--
作者：
Chen, CN;Chu, CC;Ho, THD
HVA22 是一种 ABA 和胁迫诱导基因，首先从大麦 (Hordeum vulgare L.) 中分离出来。 HVA22的同源物已在植物、动物、真菌和原生动物中发现，但在原核生物中未发现，这表明HVA22在真核生物中发挥着独特的作用。已在拟南芥中鉴定出五种 HVA22 同源物，命名为 AtHVA22a、b、c、d 和 e。这五个 AtHVA22 同源物可分为两个亚家族，AtHVA22a、b 和 c 属于一个亚家族，AtHVA22d 和 e 属于另一个亚家族。系统发育分析表明，AtHVA22d和e比AtHVA22a、b和c更接近大麦HVA22，这表明这两个亚科在单子叶植物和双子叶植物分化之前就已经分化。 AtHVA22 同源物和大麦 HVA22 的外显子分布和大小相似，表明这些基因是共同祖先的后代。 AtHVA22 同源物受 ABA、寒冷、脱水和盐胁迫的差异调节。这四种处理增强AtHVA22a、d和e表达，但对AtHVA22c表达影响很小甚至是抑制作用。 ABA 和盐胁迫诱导 AtHVA22b 表达，但冷胁迫抑制 ABA 对该基因的诱导。在五种同源物中，AtHVA22d 的表达受到这四种处理的最严格调节。一般来说，AtHVA22 同源物在花芽和花序茎中的表达水平高于在莲座丛和茎生叶中的表达水平。这些同源物在未成熟长角果中的表达水平是所有分析组织中最低的。这表明AtHVA22家族成员中的一些可能在胁迫耐受性中发挥作用，而其他成员则参与植物生殖发育。
HVA22 is an ABA- and stress-inducible gene first isolated from barley (Hordeum vulgare L.). Homologues of HVA22 have been found in plants, animals, fungi and protozoa, but not in prokaryotes, suggesting that HVA22 plays a unique role in eukaryotes. Five HVA22 homologues, designated AtHVA22a, b, c, d and e, have been identified in Arabidopsis. These five AtHVA22 homologues can be separated into two subfamilies, with AtHVA22a, b and c grouped in one subfamily and AtHVA22d and e in the other. Phylogenetic analyses show that AtHVA22d and e are closer to barley HVA22 than to AtHVA22a, b and c, suggesting that the two subfamilies had diverged before the divergence of monocots and dicots. The distribution and size of exons of AtHVA22 homologues and barley HVA22 are similar, suggesting that these genes are descendents of a common ancestor. AtHVA22 homologues are differentially regulated by ABA, cold, dehydration and salt stresses. These four treatments enhance AtHVA22a, d and e expression, but have little or even suppressive effect on AtHVA22c expression. ABA and salt stress induce AtHVA22b expression, but cold stress suppresses ABA induction of this gene. Expression of AtHVA22d is the most tightly regulated by these four treatments among the five homologues. In general, AtHVA22 homologues are expressed at a higher level in flower buds and inflorescence stems than in rosette and cauline leaves. The expression level of these homologues in immature siliques is the lowest among all tissues analyzed. It is suggested that some of these AtHVA22 family members may play a role in stress tolerance, and others are involved in plant reproductive development.