No abstract

The elongation factor GSL-Elong and myrosinase, which are essential for sulforaphane biosynthesis, were cloned for the first time from broccoli (Brassica oleracea var. italica) and were designated as Bro-GS-elong and Bro-myro. Sequence analysis of Bro-GS-elong and Bro-myro revealed that its full length cDNA was 1787 bp long and included a 1464 bp open reading frame encoding and 1846 bp long and included a 1647 bp open reading frame encoding, respectively. Bro-GS-elong and Bro-myro seem to be existed as members of multigene families in the broccoli genome and to be influenced by abiotic stresses and plant development. Bro-myro was preferentially expressed in reproductive organs, but the transcript levels of Bro-GS-elong were surpassed in vegetative organs. Both Bro-GS-elong and Bro-myro were strongly expressed at the period of sprouting, this result appeared to imply that Bro-GS-elong and Bro-myro may perform an important function in the early development on the quickly growing tissues and organs. The highest transcript levels of Bro-GS-elong and Bro-myro by MeJA treatment implied that glucosinolate-myrosinase system was primarily activated by jasmonates signaling. The results provide the basis for the glucosinolate-myrosinase system and the biotechnological manipulation of sulforaphane, a useful functional substance, in B. oleracea var. italica.

No abstract

A novel gene, denoted IbEF1isolated from sweet potato corresponded to the most abundant mRNA present in root tissue under salt stress. However, the encoded protein did not accumulate in the shoots. Transgenic tobacco plants were generated to elucidate the physiological function of IbEF1. The extent of early flowering of these plants correlated well with the level of IbEF1 expression, implicating IbEF1 as a positive regulator of flowering of tobacco plants. Over-expression of IbEF1 enhanced the AP1 gene in response to flowering time, but not floral organ development. These results demonstrate that simple manipulation of IbEF1 activity has great potential with regard to flowering time.