公开(公告)号：US5656474A

公开(公告)日：1997-08-12

申请号：US162475

申请日：1993-12-07

申请人： Zohreh Tabaeizadeh ,  Long-Xi Yu ,  Ri-Dong Chen

发明人： Zohreh Tabaeizadeh ,  Long-Xi Yu ,  Ri-Dong Chen

IPC分类号： C12N9/24 ,  C12N15/56 ,  C12N9/44

CPC分类号： C12Y302/01014 ,  C12N9/2442

摘要： Two osmotic stress- and ABA-responsive members of the endochitinase (EC 3.2.1.14) gene family has been isolated and identified from leaves of drought-stressed Lycopersicon chilense plants. The 966-base-pair insert of pcht28 encodes an acidic chitinase precursor with an amino-terminal signal peptide. The mature protein is predicted to have 229 amino acid residues with a relative molecular weight of 24,943 and pI value of 6.2. The same number in amino acids, molecular and PI value are predicted for the protein encoded by pchtI, despite of a slight variation in the DNA and amino acid sequences. Sequence analysis revealed that pcht28 and pchtI have a high degree of homology with class II chitinases (EC 3.2.1.14) from tobacco. Northern blot analysis indicated that these genes have evolved a completely different pattern of expression from others reported thus far. They are highly induced by both osmotic stress and the plant hormone abscisic acid. Southern blot analysis of genomic DNA suggested that the pcht28- and pchtI-related chitinase is encoded by a small multigene family in this species. Knowing the role of plant chitinase in plant defense against fungal pathogens, it is assumed that, besides their general defensive function, the pcht28- and pchtI-encoded chitinases may play a particular role in protecting plants from pathogen attack during water stress.

摘要翻译： 已经从干旱胁迫的番茄红叶植物的叶中分离和鉴定了内切壳酶（EC 3.2.1.14）基因家族的两个渗透胁迫和ABA响应成员。 pcht28的966-碱基对插入片段编码具有氨基末端信号肽的酸性几丁质酶前体。 预期成熟蛋白具有229个氨基酸残基，相对分子量为24,943，pI值为6.2。 对于由pchtI编码的蛋白质，预测氨基酸，分子和PI值的相同数量，尽管DNA和氨基酸序列有轻微变化。 序列分析表明，pcht28和pchtI与烟草中的II类几丁质酶（EC 3.2.1.14）具有高度的同源性。 Northern印迹分析表明，这些基因已经演变出与迄今为止报道的其他基因完全不同的表达模式。 它们都被渗透胁迫和植物激素脱落酸所诱导。 基因组DNA的Southern印迹分析表明pcht28-和pchtI相关的几丁质酶由该物种中的一个小型多基因家族编码。 了解植物几丁质酶在植物防御真菌病原体中的作用，假设pcht28和pchtI编码的几丁质酶除了具有一般的防御功能外，在水分胁迫过程中可能起到保护植物免受病原体攻击的特殊作用。