從菸草毛狀根之型態與轉錄體探討根毛農桿菌 rol 基因之功能

Abstract

Hairy root is the tumorized tissue induced when Agrobacterium rhizogenes infects plants, and is considered as the most powerful plant secondary metabolites-producing system. The formation of hairy root have been known to related to four root inducing (rol) genes rolA, rolB, rolC, and rolD that lie in the transferred DNA (T-DNA) of A. rhizogenes root inducing (Ri) plasmid. However, no studies showed how these rol genes affect hairy root architecture. Also, there is no comprehensive –omics information of how plant cell is manipulated by the rol genes. Therefore, this study tried to answer these questions by morphological and transcriptomic analysis of tobacco hairy root induced by wild type and rol deletion mutant of A. rhizogenes. Morphological analysis revealed that lacking rolB and rolC cause impaired hairy root syndrome, while lacking rolA and rolD had little or no effects. Transcriptomic comparison of rolB / rolC deleted hairy roots compared with that of wild type indicate that RolB may positively regulate lipid transport, cellular amino acid derivative biosynthesis process, response to wounding, and response to ethylene stimulus. Meanwhile, the biological processes that may be positively regulated by RolC are response to wounding, response to chemical stimulus, carbohydrate metabolic process, and lipid transport. The results revealed how rolB and rolC affect hairy root morphology and what are the corresponding biological processes they manipulated.