Key message

The DEAD-Box RNA helicase OsTOGR1 positively regulates heat stress tolerance in Chinese cabbage.

Abstract

Non-heading Chinese cabbage (Brassica rapa L. ssp. chinensis) is primarily cultivated vegetable crop in Asian countries. Heat stress is one of the major threats for its growth and yield. Numerous regulatory genes in various crops have shown to contribute thermotolerance. Among them, Thermotolerant growth required 1 (TOGR1) is an important DEAD-box RNA helicase. To examine whether its role is conserved in other crops, we constructed pCAMBIA1300-pHSP:OsTOGR1 expression vector driven by the rice small heat shock protein promoter (pHSP17.9) and successfully produced transgenic non-heading Chinese cabbage plants expressing OsTOGR1 gene via Agrobacterium-mediated vacuum infiltration transformation. In total, we generated three independent transgenic cabbage lines expressing TOGR1 gene. Expression and integration of TOGR1 was confirmed by PCR, RT-PCR and qPCR in T₁ and T₂ generations. The relative leaf electrical conductivity of transgenic seedlings was reduced subjected to high temperature (38 °C) compared to heat shock treatment (46 °C). In addition, hypocotyl length of transgenic seedlings increased compared to wild-type plants under high temperature and heat shock treatment. Furthermore, the transgenic plants exhibited higher chlorophyll content than wild-type plants under high temperature and heat shock treatment. The transgenic seeds displayed better germination under heat shock treatment. Tested heat stress-responsive genes were also up-regulated in the transgenic plants subjected to high temperature or heat shock treatment. To the best of our knowledge, this is the first report on describing the role of DAED-Box RNA helicases in improving heat stress tolerance of transgenic plants.

中文翻译：

---

核仁DEAD-Box RNA解旋酶OsTOGR1的异位表达提高了转基因大白菜的热应激耐受性

关键信息

DEAD-Box RNA 解旋酶 Os TOGR1正向调节大白菜的耐热性。

抽象的

不结球大白菜（Brassica rapa L. ssp. chinensis）是亚洲国家主要种植的蔬菜作物。热应激是其生长和产量的主要威胁之一。各种作物中的许多调节基因已显示出有助于耐热性。其中，耐热生长所需1（TOGR1）是一种重要的DEAD-box RNA解旋酶。为了检验其在其他作物中的作用是否保守，我们构建了由水稻小热休克蛋白启动子（p HSP17.9 ）驱动的pCAMBIA1300-pHSP:OsTOGR1表达载体，并通过农杆菌成功生产出表达OsTOGR1基因的转基因大白菜植物。介导真空浸润转化。总之，我们产生了三个独立的表达TOGR1基因的转基因卷心菜系。_{通过 T 1}和 T ₂中的 PCR、RT-PCR 和 qPCR 确认TOGR1的表达和整合几代人。与热休克处理（46°C）相比，转基因幼苗的相对叶片电导率在高温（38°C）下降低。此外，与野生型植物相比，在高温和热休克处理下，转基因幼苗的下胚轴长度增加。此外，转基因植物在高温和热激处理下比野生型植物表现出更高的叶绿素含量。转基因种子在热休克处理下表现出更好的发芽率。经受高温或热休克处理的转基因植物中测试的热应激反应基因也上调。据我们所知，这是第一份描述 DAED-Box RNA 解旋酶在提高转基因植物热胁迫耐受性中的作用的报告。