毛尖紫萼藓干旱胁迫cDNA文库的构建

干旱胁迫是影响植物生长发育的主要环境因素，严重影响农作物的产量。解决这个问题的有效途径是培育和利用优良的抗旱品种。应用比较功能基因组学方法筛选抗旱相关基因，并通过基因工程培育抗旱品种已成为植物遗传资源与品种改良研究的重要内容。毛尖紫萼藓（Grimmia pilifera）是典型旱生藓类，生长在向阳的裸岩上，具有很强的抗旱能力，是很好的抗旱基因资源。本研究采用SMART技术构建毛尖紫萼藓干旱cDNA文库，文库滴度为2.8×10⁵ pfu·mL^-1，重组率为91.7%，插入片段大小为500~2 000 bp，平均为800 bp。通过测序我们获得了1 045条ESTs，其中高质量的996条，通过拼接获得875个Unigenes，为进一步筛选抗旱相关基因奠定了基础。

Construction of cDNA Library in Grimmia pilifera Under Drought Stress

Drought is the major environmental factor that influences the growth of plant and accounts for significant reduction in the yields of crops. An effective approach to solve this problem is to produce drought-tolerant crops. Therefore, comparative functional genomics studies are required to identify key genes responsible for dehydration and drought stress tolerance as well as candidate genes for genetic engineering of drought stress tolerance in crop plants. Grimmia pilifera, as a common drought tolerant moss, grows in habitats of rocky outcrops, having a high ability in resisting drought stress. G.pilifera may serve as a rich genetic resource for the identification of novel genes associated with environmental stress and dehydration tolerance. To identify genes involved in drought tolerance for genetic engineering of biotic and abiotic stress tolerance in crop plants, a cDNA library was constructed with G.pilifera under drought stress by using Creater^TM SMART^TM cDNA Library Construction Kit. The total RNA was extracted by improved SDS method. The library had a titer of 2.8×10⁵ pfu·mL^-1, and the recombination rate was 91.7%. PCR amplification revealed that the insert cDNA fragments ranged mostly from 500 to 2 000 bp, with an average length of 800 bp. A total of 1 045 cDNA clones were randomly sequenced and analyzed. High-quality ESTs were obtained for 996 clones representing 875 unique sequences. The constructed cDNA library provided an essential for screening and cloning of new drought resistance associated genes of G.pilifera.