Abstract
The Nitrite Transporter (CsNitr1-S) was first cloned from cucumber. CsNitr1-S is an efflux type nitrite transporter. The CsNitr1-S is located at the plasma membrane and is anticipated to transport nitrite out of the cell at the early stage of germination or de-etiolation. To better understand the function of the CsNitr1-S, transgenic tobacco lines overexpressing and suppressing the nitrite transporter were made by inserting the CsNitr1-S in the sense and antisense directions using Agrobacterium tumefaciens. In this study, nitrate reductase, nitrite reductase, chloroplast development, and intra cellular nitrite concentrations were analysed along the course of seed germination. Results have indicated that CsNitr1-S saves the seed from a toxic effect of nitrite accumulation, which can occur before chloroplast development. The relatedness of the nitrite transporter function with other phenotypes such as drought tolerance will also be discussed.
