To improve the transformation efficiency of wheat (Triticum aestivum L.) mediated by Agrobacterium tumefaciens, we explored the possibility of employing the basal portion of wheat seedling (shoot apical meristem) as the explants. Three genotypes of wheat were transformed by A. tumefaciens carrying beta-1, 3-glucanase gene. After vernalization, the seeds to be transformed were germinated. When these seedlings grew up to 2 approximately 5 cm, their coleoptile and half of the cotyledon were cut out, and the basal portions were infected by A. tumefaciens. A total 27 T(0) transgenic plants were obtained, and the average transformation efficiency was as high as 9.82%. Evident segregation occurred in some of the T(1) plants, as was indicated by PCR and Southern blotting analysis. Investigation of the T(2) plants revealed that some transformed plants had higher resistance to powdery mildew than the controls. Northern blotting revealed that beta-1, 3-glucanase gene was normally expressed in the T(2) plants, which showed an increased resistance to powdery mildew. The results above indicate that the exogenous gene has been successfully integrated into the genome of wheat, transmitted and expressed in the transgenic progeny. From all the results above, it can be concluded that Agrobacterium inoculum to the basal portion of wheat seedling is a highly efficient and dependable transformation method. It can be developed into a practicable method for transfer of target gene into wheat.

Valtrate is a pharmacologically active epoxyiridoid ester found in the roots and rhizomes of Valeriana jatamansi Jones. The plant produces only small amounts of this metabolite naturally, and so induction of hairy roots as well as elicitation can be useful to increase its commercial production. In this study, strain R1601 of Agrobacterium rhizogenes was used to induce hairy roots in V. jatamansi, and stable hairy root cultures of V. jatamansi were established successfully. The influence of three exogenous elicitors including methyl jasmonate (MJ), jasmonic acid (JA) and salicylic acid (SA) on valtrate production in the hairy root cultures of V. jatamansi was also investigated, and the 25-day-old hairy root cultures were treated with different concentrations of the elicitors at exposure time of 7 days. This present study showed that MJ (100 mg/L) highly promoted valtrate production at 7 days after elicitation, to a level of 3.63 times higher than that of non-elicited control. SA did not significantly increase the production of valtrate. This is the first-time study to assess the elicitation of hairy root cultures to promote valtrate biosynthesis in V. jatamansi and the resulting experiments demonstrated that MJ was indeed a potent inducer of valtrate biosynthesis.

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In order to find the best screening kanamycin concentration in the genetic transformation of mustard (Brassica juncea Coss.), the seedling cotyledons of mustard were placed on bud-induced media supplemented with different kanamycin concentrations. The bud differentiation of explants was totally inhibited when the kanamycin concentration was greater than 30 mg/L. The seeds of mustard were placed on germination media supplemented with different concentrations of kanamycin. All the seedlings were white when kanamycin concentration was higher than 200 mg/L. The leaves of mustard in field were smeared with the solutions including different concentrations of kanamycin. The treated leaves showed white when kanamycin concentration was over 200 mg/L. To study the segregation of the alien gene in transgenic mustard offspring, the transgenic mustard seeds and the leaves of the transgenic mustard offspring using npt-gene as assistant selection-marker were treated with 200 mg/L kanamycin, and the results were analyzed by chi-square test. The segregation ratio in the offspring of 4 transgenic lines with single copy of transgene agreed with a ratio of 3:1. The segregation ratio in offspring of the one transgenic line with double copies was agreed with a ratio of 3:1, and the segregation ratio in offspring of the other transgenic line with double copies was agreed with ratios of 3:1 and 15:1 simultaneously. It is indispensable to thoroughly study the insert of the double copies of transgenes in transgenic mustard. PCR technology was used to confirm the above detection methods. It is concluded that applying kanamycin to screen transgenic mustard offspring is feasible.

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