次生萜类生物合成的调控

REGULATION OF PLANT SECONDARY TERPENOID BIOSYNTHESIS

克隆了青蒿单萜合成酶(芳樟醇合成酶)CDNA,发现该酶基因的转录可被伤透导。在棉花悬浮细胞中,真菌激发子诱导这两个基因的转录表达。在棉芬发育种子中,FPS基因和杜松烯合成酶基因(CAD1)随腺体的出现而大量表达,导致棉酚等倍半萜醛类的积累。在棉花幼苗和植株中,CAD1-A和CAD1-C具有不同的表达特征。

Terpenoids are products of isoprenoid pathway. The sesquiterpene synthase catalyzes formation of sesquiter-pene intermediates from farnesyl diphosphate (FPP) . We have cloned cDNAs/genes encoding ( + )-δ-cadinene synthase (CAD) and FPP synthase (FPS) from cotton, and analyzed their expression pattern. Treatment of Gossypium arboreum cultured cells with an elicitor of Verticillium dahliae dramatically induced transcription of both FPS and CAD1. Investigation of a glanded G. hisutum cultivar revealed an active biosynthesis of sesquiterpenoids in developing seeds, starting at an early cotyledon stage. In cotton seedlings and mature plants, the CAD1-A and CAD1-C genes were regulated differentially. We also isolated (3R)-linalool synthase cDNAs (QH1 and QH5) from Artemisia annua L. RT-PCR demonstrated a wounding - inducible increase in QH1 and QH5 transcription.