草地早熟禾叶基和根尖愈伤组织的诱导及相关基因的表达模式分析OA

[Objective]To establish an efficient callus induction system for Poa pratensis and identify genes po-tentially involved in callus induction.[Method]The effects of different concentrations of 2,4-dichlorophenoxyacetic acid(2-4-D),different ratios of 2,4-D to 6-benxylaminopurine(6-BA),and different carbon sources on callus induc-tion were investigated using different regions of primary leaves and radicles from aseptic seedlings of the commercial cultivar 'Barun'.The expression patterns of genes potentially associated with callus formation during the induction pro-cess were analyzed using quantitative real-time PCR.[Result]Among the six explant regions examined,only the leaf base and root tip exhibited callus-forming ability.Both explants showed the highest callus induction rates at 2,4-D concentration of 4 mg/L,reaching 86.67%and 96.67%,respectively.When maltose was used as the carbon source,callus derived from the leaf-based showed the fastest growth and the lowest browning rate.In contrast,when sucrose was used as the carbon source,the root tip exhibited a higher callus induction rate and faster growth.The expression levels of PpWOX11,PpWOX12B,PpBBM1,PpBBM2,PpBBML and PpCRL1 were highest between days 1 and 3 of callus induction in both leaf base and root-tip explants.PpWOX5 expression peaked on day 2 in leaf-base calli and on day 8 in root-tip calli.PpSET1 expression was highest on day 0 in both leaf-base and root-tip explants.[Con-clusion]Root tips were the most suitable explants for callus induction in P.pratensis.The genes PpWOX11,PpWOX12B,PpBBM1,PpBBM2,PpBBML,and PpCRL1 may play important roles in promoting callus initiation.