拟南芥干旱相关突变体的远红外筛选及基因克隆

Use of Infrared Thermal Imaging to Isolate and Gene Cloning of Drought-related Mutants in Arabidopsis thaliana

干旱胁迫是影响植物生长发育的主要限制因素之一。到目前为止,许多研究都仅关注于植物对干旱反应的信号转导网络,而对其中一些很重要的中间成分却知之甚少。保卫细胞定位于植物叶片的表皮中,控制二氧化碳的吸收以及水分的散失,已经成为一种高度特化的细胞体系,可用来研究植物早期干旱信号转导机制。控制气孔的开度在提高植物的抗旱性方面具有重要意义。通过使用远红外热成像仪检测植物叶片表面温度的微小差异,我们成功地筛选并获得了拟南芥(Arabidopsis thaliana)干旱敏感突变体doi1。在干旱胁迫条件下,该突变体表现为叶面温度低于野生型,且失水率比野生型高。利用TAIL-PCR技术成功克隆到该突变体基因NCED3,并利用RT-PCR方法验证了TAIL-PCR结果的可靠性。

Drought stress is one of the major limitations to plant growth and development. To date, many studies have focused on network signaling pathways that regulate plant responses to drought. However, many of the principal signaling components and their interactions remain largely unknown. Guard cells, located in the epidermis of plant leaves, control both the influx of CO2 and water loss during transpiration, and have become a highly developed system for dissecting early drought signal-transduction mechanisms in plants. So it has central effects on controlling of water balance or improving drought tolerance to retaining optimal aperture of stomata in plants. Recently, infrared thermal cameras have been used to monitor the subtle differences in leaf temperature in plants. We used this system to screen a drought- sensitive mutant, doi1, in Arabidopsis. This mutant showed cooler leaf temperature and faster water loss rate than did the wild type under drought stress. The mutant gene NCED3 in doi1 was cloned by the TAIL-PCR method, and RT-PCR was used to confirm the authenticity of the TAIL-PCR result.