XVI International Botanical Congess

Lotus survives defoliation and environmental stress by relying on root organic reserves. Research in Lotus has focused on root starches and sugars. Recent work with other forage legumes suggests that root N reserves have a key role in stress tolerance. Roots of alfalfa (Medicago sativa L.) accumulate large quantities of three distinct polypeptides that serve as a pool of reserve N. These vegetative storage proteins constitute 1/3 of the root protein pool, and like root starch, are preferentially depleted when shoot growth resumes in spring and after defoliation in summer. Progress to improve Lotus stress tolerance is hindered, in part, by our limited understanding of organic reserves in this species, and mechanisms controlling their synthesis and degradation. This paper will review our current understanding of root organic reserves in Lotus, and propose avenues for future research.