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本研究以不同磷效率的4个柱花草基因型L6、L8、L10和Y3为材料,分析不同磷源处理对柱花草生物量、全磷含量、根系酸性磷酸酶活性和紫色酸性磷酸酶基因SgPA Ps表达的影响.结果表明,相对于不加磷处理(-P),添加外源DNA (+DNA)和速效磷处理(+P)均显著增加了柱花草的干重和全磷含量,但是,在添加外源DNA处理下,磷高效基因型L10与Y3的干重和全磷含量显著高于磷低效基因型L6与L8.在不加磷和添加外源DNA处理下,柱花草的根系内源和分泌酸性磷酸酶活性均显著增加,但L10和Y3的根系分泌酸性磷酸酶活性显著高于L6和L8.SgPAP7和SgPAP10在4个柱花草基因型的根系中均受低磷胁迫(不加磷和添加外源DNA处理)诱导上调表达,且在L10和Y3中的相对表达量显著高于L6和L8.以上结果表明,磷高效柱花草基因型L10和Y3具有较高的根系分泌酸性磷酸酶活性和较强的活化利用外源DNA能力.当体内磷缺乏时,柱花草通过增加SgPAP7和SgPAP10的表达来调控酸性磷酸酶活性,从而增加对外源DNA的活化利用.本研究为磷高效柱花草的选育和遗传改良提供了理论依据和候选基因资源.“,”Plant biomass,phosphorus (P) content,root acid phosphatase (APase) activity and transcripts of SgPA Ps were analyzed in four stylo (Stylosanthes) genotypes,L6,L8,L10 and Y3,with contrasting P efficiency,under different P treatments.Results showed that plant dry weight and total P content significantly increased with application of both exogenous DNA (+DNA) and available P (+P) compared to the treatment of no P (-P) addition.Plant dry weight and total P content in L10 and Y3 were higher than those in L6 and L8 with exogenous DNA treatment.Root internal and root secreted APase activities significantly increased in the treatment of exogenous DNA and no P treatments.Additionally,root secreted APase activities in L10 and Y3 were higher than those in L6 and L8,and expression levels of SgPAP7 and SgPAP10 were up-regulated by P deficiency in the four tested stylo roots.Furthermore,there was a higher abundance of transcripts of SgPAP7 and SgPAP10 in L10 and Y3 than those in L6 and L8 under P deficiency.These results suggested that the P efficient stylo genotypes,L10 and Y3,exhibited superior root secreted APase activities and DNA utilization capability,which might be regulated by the expressions of SgPAP7 and SgPAP10 under low P stress.Our results provided theoretical basis and gene resources for selecting and improving stylo varieties adapted to low P stress.