纤维植物罗布麻发根的诱导及植株再生

Agrobacterium rhizogenes-mediated Transformation and Regeneration of the Apocynum venetum

摘要:

利用3种发根农杆菌(LBA9402、R601、和R1000)转化纤维植物罗布麻无菌种子苗的根茎叶不同外植体部位, 首次诱导其生成发根并实现了直接由发根途径的植株再生。罗布麻发根诱导与所用的发根农杆菌菌株, 外植体部位及光周期密切相关。发根农杆菌LBA9402感染罗布麻的根外植体, 实现了最高转化率达100%。与LBA9402及R601相比,被发根农杆菌R1000感染的根外植体适合在黑暗环境下培养, 其诱导生成的发根密度可达平均每个外植体22条。在不加激素的1/2 MS培养基上, LBA9402和R601诱导产生的发根可以诱导生成不定芽, 不定芽诱导率达20%。不定芽切下后, 在不加激素的1/2 MS培养基上2周内可以诱导生根。通过聚合酶链式反应(PCR)对发根及再生植株进行了鉴定, 证明发根农杆菌的T-DNA插入了植物的基因组。本研究为罗布麻的分子育种建立了稳定的转化及再生体系, 为下一步通过转入外源基因改善其农艺性状奠定了基础。

Abstract:

A system for the Agrobacterium rhizogenes-mediated transformation and plant regeneration of A. venetum has been developed. The highest transformation frequency was 100%, achieved by using strain LBA9402 with root explants. The highest density of hairy roots reached 22 when root explants transformed by R1000 cultured in the dark. Adventitious shoots were obtained from profusely branched, fast-growing (type PBF) hairy roots, and the adventitious shoot induction frequency was 20%. Regenerated shoots rooted easily on hormone-free 1/2 MS solid medium in 2 weeks. Approximately 1/3 regenerated plants derived from hairy roots exhibited prolific roots with shortened internodes. Whereas other regenerated plants showed another phenotype: long internodes, strong stems, and fleshy blades. However, all regenerated plants displayed a relatively fast development procedure and stronger than the aseptic seedlings. Polymerase chain reaction (PCR) analyses confirmed the hairy root lines and regenerated plants were induced by A. rhizogenes.