Expression of Arabidopsis Ornithine Aminotransferase (AtOAT) encoded gene enhances multiple abiotic stress tolerances in wheat
Expression of Arabidopsis Ornithine Aminotransferase (AtOAT) encoded gene enhances multiple abiotic stress tolerances in wheat
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DOI：
10.1007/s00299-021-02699-0
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发表时间：
2021-05-05
影响因子：
6.2
通讯作者：
Ye, Xingguo
中科院分区：
文献类型：
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作者：
Anwar, Alia;Wang, Ke;Ye, Xingguo
关键信息拟南芥鸟氨酸氨基转移酶（AtOAT）编码基因的异位表达增强了小麦的耐旱性和耐盐性。证实了OAT在小麦脯氨酸生物合成中起作用。脯氨酸（Pro）积累是植物对生物和非生物胁迫的共同反应。鸟氨酸氨基转移酶（OAT）是一种依赖于5-磷酸吡哆醛的酶，参与植物脯氨酸的生物合成。在应激条件下，脯氨酸通过谷氨酸和鸟氨酸途径合成。OAT是鸟氨酸途径中的关键酶。在这项研究中，一个OAT基因AtOAT从拟南芥中表达小麦在干旱，盐，热胁迫条件下的功能特性。我们发现AtOAT基因的表达通过提高脯氨酸含量和过氧化物酶活性来增强小麦对干旱和盐胁迫的耐受性。此外，AtOAT基因的表达也证实了转基因小麦对热胁迫的部分耐受性。实时荧光定量PCR（qRT-PCR）分析表明，AtOAT基因的导入上调了脯氨酸生物合成相关基因TaOAT、TaP 5CS和TaP 5CR的表达，下调了脯氨酸代谢相关基因TaP 5CDH的表达。此外，与鸟氨酸途径相关的基因（Orn-OAT-P5 C/GSA-P5 CR-Pro）也沿着与谷氨酸途径相关的基因（Glu-P5 CS-P5 C/GSA-P5 CR-Pro）表达上调。因此，AtOAT基因的表达可能通过上调脯氨酸合成相关基因的表达，下调脯氨酸分解代谢相关基因的表达，从而调节脯氨酸的合成，从而增强小麦的非生物胁迫耐性。
Key message The drought and salt tolerances of wheat were enhanced by ectopic expression of the Arabidopsis ornithine aminotransferase (AtOAT) encoded gene. The OAT was confirmed to play a role in proline biosynthesis in wheat. Proline (Pro) accumulation is a common response to both abiotic and biotic stresses in plants. Ornithine aminotransferase (OAT) is pyridoxal-5-phosphate dependent enzyme involved in plant proline biosynthesis. During stress condition, proline is synthesized via glutamate and ornithine pathways. The OAT is the key enzyme in ornithine pathway. In this study, an OAT gene AtOAT from Arabidopsis was expressed in wheat for its functional characterization under drought, salinity, and heat stress conditions. We found that the expression of AtOAT enhanced the drought and salt stress tolerances of wheat by increasing the proline content and peroxidase activity. In addition, it was confirmed that the expression of AtOAT also played a partial tolerance to heat stress in the transgenic wheat plants. Moreover, quantitative real-time PCR (qRT-PCR) analysis showed that the transformation of AtOAT up-regulated the expression of the proline biosynthesis associated genes TaOAT, TaP5CS, and TaP5CR, and down-regulated that of the proline catabolism related gene TaP5CDH in the transgenic plants under stress conditions. Moreover, the genes involved in ornithine pathway (Orn-OAT-P5C/GSA-P5CR-Pro) were up-regulated along with the up-regulation of those genes involved in glutamate pathway (Glu-P5CS-P5C/GSA-P5CR-Pro). Therefore, we concluded that the expression of AtOAT enhanced wheat abiotic tolerance via modifying the proline biosynthesis by up-regulating the expression of the proline biosynthesis-associated genes and down-regulating that of the proline catabolic gene under stresses condition.