Lima Joni Esrom, Benedito Vagner Augusto, Figueira Antonio, Peres Lázaro Eustáquio Pereira
Centro de Energia Nuclear na Agricultura, USP, Av. Centenário, 303, Piracicaba, SP, 13400-970, Brazil.
Plant Cell Rep. 2009 Aug;28(8):1169-77. doi: 10.1007/s00299-009-0718-y. Epub 2009 May 30.
We analyzed the impact of ethylene and auxin disturbances on callus, shoots and Agrobacterium rhizogenes-induced hairy root formation in tomato (Solanum lycopersicum L.). The auxin low-sensitivity dgt mutation showed little hairy root initiation, whereas the ethylene low-sensitivity Nr mutation did not differ from the control Micro-Tom cultivar. Micro-Tom and dgt hairy roots containing auxin sensitivity/biosynthesis rol and aux genes formed prominent callus onto media supplemented with cytokinin. Under the same conditions, Nr hairy roots did not form callus. Double mutants combining Rg1, a mutation conferring elevated shoot formation capacity, with either dgt or Nr produced explants that formed shoots with little callus proliferation. The presence of rol + aux genes in Rg1 hairy roots prevented shoot formation. Taken together, the results suggest that although ethylene does not affect hairy root induction, as auxin does, it may be necessary for auxin-induced callus formation in tomato. Moreover, excess auxin prevents shoot formation in Rg1.
我们分析了乙烯和生长素紊乱对番茄（Solanum lycopersicum L.）愈伤组织、芽以及发根农杆菌诱导的毛状根形成的影响。生长素低敏感性dgt突变体几乎没有毛状根起始，而乙烯低敏感性Nr突变体与对照Micro-Tom品种没有差异。含有生长素敏感性/生物合成rol和aux基因的Micro-Tom和dgt毛状根在添加细胞分裂素的培养基上形成了显著的愈伤组织。在相同条件下，Nr毛状根没有形成愈伤组织。将具有提高芽形成能力的Rg1突变体与dgt或Nr组合的双突变体产生的外植体形成了芽，且愈伤组织增殖很少。Rg1毛状根中rol + aux基因的存在阻止了芽的形成。综合来看，结果表明，虽然乙烯不像生长素那样影响毛状根诱导，但它可能是番茄中生长素诱导愈伤组织形成所必需的。此外，过量的生长素会阻止Rg1中芽的形成。
