Promoter Analysis and Transcriptional Profiling of Ginkgo biloba 3-Hydroxy-3-Methylglutaryl Coenzyme A Reductase (GbHMGR) gene in Abiotic Stress Responses

• Main Authors: Yongling LIAO, Feng XU, Xiaohua HUANG, Weiwei ZHANG, Hua CHENG, Linling LI, Shuiyuan CHENG, Yongbao SHEN
• Format: Article
• Language: English
• Published: AcademicPres 2015-04-01
• Series: Notulae Botanicae Horti Agrobotanici Cluj-Napoca
• Online Access: http://www.notulaebotanicae.ro/index.php/nbha/article/view/9416
• ISSN: 0255-965X; 1842-4309

</style><p class="MsoNormal" style="text-align:justify;text-indent:14.2pt"><span lang="EN-US" style="font-family: 'Garamond Premr Pro',serif; color: black">The terpene trilactones (TTLs) are believed to be important for the pharmacological properties of <i>Ginkgo biloba</i> leaves extract. 3-Hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) is a critical enzyme involved in the biosynthetic pathway of TTLs. In this study, an 1.2-kb fragment of 5</span><font face="Garamond Premr Pro,serif"><span lang="EN-US" style="color:black">’</span></font><span lang="EN-US" style="font-family: 'Garamond Premr Pro',serif; color: black"> flanking region of the <i>HMGR</i> gene (<i>GbHMGR</i>), was isolated from <i>G. biloba</i> by genome walking. Extensive sequence analysis revealed the presence of evolutionarily conserved and over-represented putative <i>cis</i>-acting elements in light-regulated transcription,&nbsp; hormone signaling (gibberellic acid, jasmonate and salicylic acid), elicitor and stress responses (cold/dehydration responses), and plant defense signaling (W-box/WRKY) that are common to the promoter region of <i>GbHMGR</i>. </span><span lang="EN-US" style="font-family: 'Garamond Premr Pro',serif; font-weight: normal">EMSA analysis suggested possible functionality of W-box in <i>GbHMGR</i> promoter region. </span><span lang="EN-US" style="font-family: 'Garamond Premr Pro',serif; color: black">The behavior of gene transcripts in ginkgo callus upon light, low temperature, MeJA and SA treatments further verified the regulatory function of <i>GbHMGR</i> promoter. A significant positive relationship between gene expression level and total TTL contents suggested that <i>GbHMGR</i> might be one of key genes involved in TTL biosynthesis in <i>G. biloba</i>.</span></p>