褐脉少花龙葵毛状根的诱导、培养及其澳洲茄胺的产生

利用发根农杆茵的遗传转化和液体培养技术,研究了褐脉少花龙葵(solanum nigrum L.Var.Dauciforum)毛状根的诱导和离体培养及其澳洲茄胺的产生以及液体培养过程中培养基中N源和钙的消耗变化.结果表明.发根农杆菌ATCC15834感染褐脉少花龙葵叶片外植体5 d后产生毛状根.感染25d后,约90%的叶片外植体产生毛状根.毛状根能在无外源生长调节剂的MS固体和体培养基上自主生长.PCR扩增结果显示发根农杆菌Ri质粒的rilB和rolC基因已在少花龙葵毛状根基因组中整合并得到表达.所产生的毛状根能产生药用次生物质澳洲茄胺,其含量约为非转化植株根的1.3倍,达到582.05μg/g干重.少花龙葵毛状根液体培养0-5 d内处于生长迟滞期、5-15 d为快速生长期、15d后进入生长平台期.培养基的硝态氮和铵态氮在毛状根液体培养过程中被逐渐吸收和消耗,至培养15 d时铵态氮被消耗殆尽.而硝态氮仍剩余44.7%;培养基中钙的浓度在培养过程中虽逐渐降低,但在培养25d时仍未被完全消耗,其浓度约为起始浓度的43.5%.该结果为今后设计合适的培养基来规模培养褐脉少花龙葵毛状根生产药用次生物质澳洲茄胺提供了可能性.

INDUCTION AND IN VITRO CULTURE OF HAIRY ROOTS OF SOLANUM NIGRUM L. VAR. PAUCIFLORUM LIOU AND ITSSOLASODINE PRODUCTION

By using genetic transformation of Agrobacterium rhizogenes and liquid culture, induction and culture conditions for Solanum nigrum L. var. pauciflorum Liou hairy roots and its solasodine production and consumption changes of N resource and calcium in the medium during liquid culture were investigated. The results showed that hairy roots could be initiated from the cut edges of leaf explants 5 days after inoculation with the strain of A. rhizogenes ATCC15834. The percentage of rooted leaf explants 25 days after infection was more than 90%. Hairy roots could grow rapidly on solid or liquid growth regulator-free MS medium. The PCR amplification of rol genes and virC gene showed that rol genes of Ri plasmid of A. rhizogenes were integrated in the genome of transformed hairy roots of S. nigrum L var pauciflorum. The hairy roots could produce medicinal secondary metabolites solasodine and the amount of solasodine in the hairy root cultures reached a level of 582.05 microg/g dry weight and was 1.31 times as much as those in the untransformed roots. The hairy roots grew very slowly in 0-5 days in the liquid medium, then, very fast from 5 to 15 days. During liquid culture, NO3(-) and NH4(+) in the medium were gradually absorbed and utilized by hairy roots. NH4(+) -N of the medium was used up at day 15 of the culture, while NO3(-) in the medium was not used up, the content of which was 44.7% of the initial amount. Ca2+ of the medium was gradually absorbed and utilized during liquid culture and it was not used up at day 25, the content of which was still 43.5% of the initial amount. The results presented here had provided the possibilities on how to prepare optimum medium for large scale cultivation and production of solasodine from S. nigrum L. var. pauciflorum hairy roots.