Transgenic lines of creeping bent grass were generated by Agrobacterium-mediated transformation with the VuNCED1 which was cloned from cow pea has a homology to 9-cis-epoxycarotenoid dioxygenase, which is supposed to be involved in abscisic acid (ABA) biosynthesis. ABA, a cleavage product of carotenoids, is involved in stress responses in plants. The limiting step of ABA biosynthesis in plants is presumably the cleavage of 9-cis-epoxycarotenoids, the first committed step of ABA biosynthesis. Molecular analyses of transgenic lines as performed by Southern hybridization genomic DNA-PCR revealed integration of the VuNCED1. Challenge studies performed with transgenic plants by exposure to salt stress (up to 10 dS m À1 ) and water stress (up to 75%) for 10 weeks, revealed that more than 50% of the transgenic plants could survive NaCl and drought stress whereas wild-type was not. ABA levels were measured under drought and normal conditions, endogenous ABA was dramatically increased by drought and NaCl stress in transgenic plants. These results indicate that it is possible to manipulate ABA levels in plants by over expressing the key regulatory gene in ABA biosynthesis and that stress tolerance can be improved by increasing ABA levels.

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MADS-box genes encode a family of transcription factors, which control developmental processes in flowering plants ranging from flower to root development. During the last few years increasing evidence point to more general roles of these factors not only in the control of flowering time, but also in other reproductive processes. However, they are also expressed in roots, stems and leaves. These results suggest that their function may be much more diverse than those involved in flowering, and the possibility of uncovering new roles for MADS-box genes in plant development. Here, we specifically explore the role of the STMADS subfamily in development of vegetative structures. This subfamily continues to grow, providing new insight into the vegetative development of other plant species and how it is distinct from the one in Arabidopsis is investigated.

In order to study disease resistance mechanisms in rice against the rice blast fungus Magnaporthe grisea, we screened fungal elicitor-responsive genes from rice suspension-cultured cells treated with fungal elicitors employing differential hybridization (DH). By DH screening, 31 distinct rice clones were isolated and a majority of them were full-length cDNAs encoding pathogenesisrelated (PR) genes. Sixteen of the 31 genes were upregulated at 4, 8, and 12 h following fungal elicitor treatment. To elucidate the effect of signal molecules and biotic elicitors on the regulation of rice defense genes, we further characterized the transcriptional expression patterns of representative isolated PR genes; OsGlu1, OsGlu2, OsTLP, OsRLK, and OsPR-10, following treatment with fungal elicitor, phytohormones, cycloheximide, and inhibitors of protein phosphorylation. Jasmonic acid (JA) induced transcriptional expression of OsGlu1, OsTLP, and OsRLK, but not of OsGlu2 and OsPR-10 at any of the tested time points. Salicylic acid (SA) and abscisic acid weakly induced the expression of OsTLP and OsRLK. SA showed an antagonistic effect with fungal elicitor and JA. Cycloheximide suppressed all these genes upon elicitor treatment, except for OsGlu2. Staurosporine only induced the expression of OsRLK. Application of calyculin A strongly induced OsRLK expression, but suppressed the expression of OsGlu2. Our study yielded a number of PR genes that play a role in defense mechanisms against the rice blast fungus, as well as contribute towards the elucidation of crosstalk between phytohormones and other modifications during defense signaling.