Seed-specific overexpression of antioxidant genes in Arabidopsis enhances oxidative stress tolerance during germination and early seedling growth.
Seed-specific overexpression of antioxidant genes in Arabidopsis enhances oxidative stress tolerance during germination and early seedling growth.
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DOI：
10.1111/j.1467-7652.2010.00509.x
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发表时间：
2010-09
影响因子：
13.8
通讯作者：
D. Xi;Wu Liu;Guo-dong Yang;Changai Wu;C. Zheng
中科院分区：
文献类型：
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作者：
D. Xi;Wu Liu;Guo-dong Yang;Changai Wu;C. Zheng
酶促和非酶促抗氧化剂在非生物胁迫耐受中发挥重要作用。为了提高种子对氧化应激的抵抗力，使用来自拟南芥的At2S3启动子以种子特异性的方式实现抗氧化剂的过度表达。该启动子被证明能够驱动目标基因在种子相关器官（包括长角果、成熟种子和早期幼苗）中高水平表达，从而使其在植物中的分子农业应用成为可能。随后，编码锰超氧化物歧化酶（MSD1）、过氧化氢酶（CAT1）和尿黑酸植基转移酶（HPT1，负责生育酚生物合成途径中第一个关键反应）的基因在At2S3启动子的控制下在拟南芥中过度表达。通过异花授粉产生共表达两种酶的双过表达子和三过表达子。在相应的过量生产线中，Mn-SOD 和总 CAT 活性以及 γ-生育酚含量显着增加。此外，与野生型相比，单一MSD1转基因、双重和三重过表达子在种子萌发和早期幼苗生长过程中表现出显着增强的氧化应激耐受性。有趣的是，由于 MSD1 过表达，在单个 MSD1 转基因品系中还观察到总 CAT 活性增加。总之，种子中 Mn-SOD 和 CAT 活性的联合增加对于拟南芥早期发育阶段抗氧化能力的提高起着至关重要的作用。
Enzymatic and non-enzymatic antioxidants play important roles in the tolerance of abiotic stress. To increase the resistance of seeds to oxidative stress, At2S3 promoter from Arabidopsis was used to achieve overexpression of the antioxidants in a seed-specific manner. This promoter was shown to be capable of driving the target gene to have a high level of expression in seed-related organs, including siliques, mature seeds, and early seedlings, thus making its molecular farming applications in plants possible. Subsequently, genes encoding Mn-superoxide dismutase (MSD1), catalase (CAT1), and homogentisate phytyltransferase (HPT1, responsible for the first committed reaction in the tocopherol biosynthesis pathway) were overexpressed in Arabidopsis under the control of the At2S3 promoter. Double overexpressers co-expressing two enzymes and triple overexpressers were produced by cross pollination. Mn-SOD and total CAT activities, as well as gamma-tocopherol content, significantly increased in the corresponding overproduction lines. Moreover, single MSD1-transgene, double, and triple overexpressers displayed remarkably enhanced oxidative stress tolerance compared to wild type during seed germination and early seedling growth. Interestingly, an increase in the total CAT activity was also observed in the single MSD1-transgenic lines as a result of MSD1 overexpression. Together, the combined increase in Mn-SOD and CAT activities in seeds plays an essential role in the improvement of antioxidant capacity at early developmental stage in Arabidopsis.