烟草发状根的诱导和植株再生

Hairy root induction and plant regeneration in Nicotiana tabacum

发根农杆菌Ar1334工程菌株与烟草叶片共培养,诱导的根在MS无激素培养基上呈现旺盛的生长态势和典型的发状根结构特点,并在附加0.5mg/mL KT的MS培养基上实现了植株再生。发状根经PCR检测扩增出了500bp的rolC目的片断,组织化学检测也证实了GUS基因在发状根及再生植株叶片中的表达。该体系为利用发状根进行外源基因表达,并通过大量培养进行物质生产奠定了基础。

Hairy roots were induced from tobacco leaves after co-cultured with Agrobacteriμm rhizogenes Arl334 harbouring agropin type pRi1855 and binary vector pIG121HM. Root with many hairs and branches grew vigorously towards all directions on MS medium without any plant hormone. The structure of the hairy root tip is different from that of ordinary root. Without typical root cap maybe the main cause of losing the geotropism of hairy root. Plantlet regenerated from hairy root when cultured on MS medium supplement with 0. 5mg/mL KT. A 560 bp fragment was amplified from the genomic DNA of hairy root by PCR using primes of rolC which was one of the four genes related to hairy root induction located on TL-DNA of Ri plasmid. Blue dots were discovered on the hairy root tips and the leaves of plantlet regenerated from hairy root after dipped into X-gluc solution at 37℃ for one night. These results proved tobacco hairy roots could be an efficient culture system to accumulate valuable substance and an ideal pathway for plant breeding through exogenous genes expressing.