Isolation and characterization of four ascorbate peroxidase cDNAs responsive to water deficit in cowpea leaves
Isolation and characterization of four ascorbate peroxidase cDNAs responsive to water deficit in cowpea leaves
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DOI：
10.1093/aob/mcj010
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发表时间：
2006-01-01
期刊：
影响因子：
4.2
通讯作者：
Zuily-Fodil, Y
中科院分区：
文献类型：
--
作者：
D'Arcy-Lameta, A;Ferrari-Iliou, R;Zuily-Fodil, Y
背景和目的非生物胁迫刺激植物组织中活性氧的形成。在抗氧化机制中，抗坏血酸过氧化物酶（APX）对H2 O2的解毒作用起着重要作用。几种APX异构体存在于植物细胞中，很少单独研究。本研究的目的是研究豇豆（Vigna unguiculata）叶片细胞质、过氧化物酶体、基质和类囊体APX基因表达对进行性干旱、快速脱水和外源脱落酸处理的响应plants.center。以耐旱的‘EPACE-1’和干旱敏感的‘1183’为材料，采用隔水灌溉的方法对长爪沙枣进行干旱胁迫处理。将离体叶片风干或用外源脱落酸处理。通过PCR分离APX cDNA并克隆到质粒载体中。使用逆转录研究基因表达的变化PCR.center dot Key Results分离并表征了4个新的编码推定的胞质、过氧化物酶体和叶绿体（基质和类囊体）APX的长爪野豌豆cDNA。在不同的处理，更高的增加，在稳态转录水平的细胞质和过氧化物酶体APX基因观察到在'1183'与'EPACE-1'相比。另一方面，叶绿体APX基因的表达被刺激更早的耐受品种时，提交渐进的drought.center.结论水分亏缺诱导的差异APX基因的转录积累的两个品种之间的相关各自的耐旱性。叶绿体APX基因在耐受性植物中对进行性水分亏缺的早期反应，表明在其生产场所有效地解毒活性氧的能力。更敏感的“1183”也能够通过激活其整套APX基因来响应干旱。
center dot Background and Aims Abiotic stresses stimulate formation of active oxygen species in plant tissues. Among antioxidant mechanisms, H2O2 detoxication by ascorbate peroxidases (APX) plays an important role. Several APX isoforms exist in plant cells, and they have rarely been studied separately. The aim of this work was to study changes in cytosolic, peroxisomal, stromatic and thylakoid APX gene expression in response to progressive drought, rapid desiccation and application of exogenous abscisic acid in the leaves of cowpea (Vigna unguiculata) plants.center dot Methods Two cowpea (V. unguiculata) cultivars, 'EPACE-1' which is drought-tolerant and '1183'which is drought-sensitive, were submitted to drought stress by withholding irrigation. Detached leaves were air-dried or treated with exogenous abscisic acid. APX cDNAs were isolated by PCR and cloned in plasmid vectors. Changes in gene expression were studied using reverse-transcription PCR.center dot Key Results Four new V. unguiculata cDNAs encoding putative cytosolic, peroxisomal and chloroplastic (stromatic and thylakoidal) APX were isolated and characterized. In response to the different treatments, higher increases in steady-state transcript levels of the cytoplasmic and peroxisomal APX genes were observed in '1183' compared with 'EPACE-1'. On the other hand, the expression of the chloroplastic APX genes was stimulated earlier in the tolerant cultivar when submitted to progressive drought.center dot Conclusions Water deficit induced differences in transcript accumulation of APX genes between the two cultivars that were related to their respective tolerance to drought. Chloroplastic APX genes responded early to progressive water deficit in the tolerant plant, suggesting a capacity to efficiently detoxify active oxygen species at their production site. The more sensitive '1183' was also able to respond to drought by activating its whole set of APX genes.