Chloride is unique amongst the plant elements. Although it is widely held that chloride is a micronutrient it can accumulate in plants to macronutrient levels without the plant incurring a penalty. Its been an area of research that has been relatively neglected until recently but research into chloride transport has taken off over the last few years. For instance, there have a number of papers from several groups in the last 12 months that have given us insights into the roles of chloride and how its transport to the shoots is controlled. Highlights include:
- The identification of the first protein (NPF2.4) that directly controls transfer of chloride from the root to the xylem – the rate limiting step in shoot accumulation of chloride (our paper in Plant Physiology)
- The identification of a second protein that controls transfer of chloride to the shoot (SLAH1) (our paper in J Exp Botany)
- The finding that SLAH1 interacts with SLAH3 to selectively gate chloride and nitrate transfer into the xylem (from the groups of Hedrich & Colmenero-Flores)
- Chloride can take on ‘macronutrient-like’ roles in plants, aiding biomass production (from the Colmenero-Flores group)
- More insights into the role of the cation chloride co-transporter protein in plants (from our group in Arabidopsis and JF Ma’s group for rice)
Looks like the this subject is primed for making some rapid progress over the next few years.