Endosymbiotic bacteria such as Bacillus subtilis, a safe organism involved in disease control, drought tolerance and growth promotion in plants have recently been isolated from leaf, stem and bark, tissues of Hevea brasiliensis. The abiotic (drought and low temperature) and biotic (various diseases) stress related genes which are normally expressed in Hevea are neither sufficient to overcome the unfavourable conditions being experienced in the traditional as well as non-traditional regions nor the expression of chitinase gene originally present in the genome of Hevea, is sufficient to provide tolerance to the fungal infections. To escape from such major fungal pathogens like Phytophthora, Corynespora, Colletotrichum sp., expression of antifungal proteins like chitinase and other pathogenesis related proteins should be maintained at higher levels. Developing transgenic plants with desirable genes is a time-consuming process in Hevea. Therefore, attempts were made to study the colonizing capacity of endosymbiotic Bacillus subtilis and to standardize a suitable transformation protocol for these endosymbionts in order to over-express antifungal genes which may have direct impact on spreading of fungal diseases in Hevea. A Bacillus subtilis specific, pHT43 expression secretion vector was employed for this purpose and the developments are discussed in this report.
Keywords: Hevea brasiliensis, Endosymbionts, B. subtilis, transformation protocol, expression secretion vector