Agrobacterium-mediated Transformation Of Chinese Jujube With TaPT2Gene

Chinese jujube (Ziziphus jujuba Mill.) is native to China where it has been the mostimportant dry fruit. Phosphorus is one of the necessary macronutrients for plants．The soilis always lack of phosphate. The phosphate transporters, mediators in plants used for Piuptake and transportation, play an important role in regulating the acquisition andutilization of Pi. In order to obtain transgenic Chinese jujube with traits of efficient uptakeand utilization of Pi and tolerance to Pi deficiency, agrobacterium-mediatedtransformation was used to improve Chinese jujube in this study. The high efficientregeneration system of adventitious shoots from leaves has been established and theAgrobacterium-mediated transformation of wheat phosphate transporter genes(TaPT2) hasbeen achieved in Chinese jujube.The main results are as follows:1. A high efficient regeneration system of adventitious shoots from leaves has beenestablished. The difference of the rate of callus induced from leaves among‘Yueguangzao’,‘Dongzao’ and ‘Muzao’ is not significant. However, the regeneration ofadventitious buds differs very much. Ratios of callus achieved100%in three cultivarsleaves in medium MS+maltose20g/L+agar5g/L+TDZ1.0mg/L+IBA0.1mg/L+AgNO31.0mg/L. In medium MS+sugar30g/L+agar5g/L+IBA0.2mg/L+6-BA0.8mg/L, the adventitious bud rate of ‘Dongzao’ and ‘Yueguangzao’ was higher than‘Muzao’. Both of them exceeded93%, while ‘Muzao’ was only66.63%. Theadeventitious bud rate obviously changed when mediums were separately added GA3、6-BA、TDZ. The vitrification of adventitious buds could be avoided in the medium MS+sugar30g/L+agar5g/L+IBA0.2mg/L+6-BA0.8~1.2mg/L, which the adventitious budrate and the average number of buds in per leaf block respectively reached93.3%and3.53. In addition, AS （Acetosyringone）100mg/L significantly accelerated theadventitious bud formation of ‘Dongzao’ and the average number of buds in per piece ofleaf achieved7.30. However, AS200mg/L in medium would lead to bud deformity.2. Determination of the selecting pressure of leaf regeneration. When Basta0.4mg/Lwas added to a medium, leaves would not produce adventitious bud but differentiation would not stop, which could serve as selecting pressure of the regeneration of leaves.Basta0.6mg/L could be used as shoot growth selecting pressure.3. The establishment of the genetic transgenic system of ‘Muzao’ leaves. The optimalconditions were determined as follows: dissected, wounded by needle, preconditioned onpre-conditioning medium for1d, infected with Agrobacterium (OD600=0.6~0.8) for5min,and then cultured in the medium of MS+maltose20g/L+agar5g/L+TDZ1.0mg/L+IBA0.1mg/L for1~3days at24℃without light. The induction rate of transformation was8.75%.4. TaPT2was firstly transferred into ‘Muzao’ and22transgenic plants were obtained.It was preliminarily proved that the foreign genes hade been transferred into genomes ofChinese jujube. Morphology feature and total phosphorus content under low-Pi conditionindicated the foreign genes of two plants have been expressed.