Insights into carotenoid dynamics in non-foliar photosynthetic tissues of avocado.

摘要: Leaves are the main photosynthetically active tissues in most plants. However, stems and fruits also important for overall carbon balance of plant because their contribution to fixation CO(2) released by respiration. Photosynthesis could not be possible without a complete set photoprotection mechanisms, which include ubiquitous violaxanthin (V) cycle taxonomically restricted lutein epoxide (Lx) cycle. In this work, we characterise carotenoid stoichiometry photosynthetic avocado comparison with that leaves specifically whether Lx is present these it involved light-driven Avocado was selected as model species study both cycles were functional non-foliar structures (stems fruits). An unusual pigment composition observed fruit, high content cis-V cis-Lx, suggesting different function. stems, xanthophylls de-epoxidated upon illumination, but only V recovered dark, indicating existence 'truncated' when its pool higher than threshold 30 mmol mol(-1) chlorophyll, non-photoconvertible Lx. We conclude that, at least dynamic regulation activity depend on