Chlorophyll breakdown in senescent banana leaves: catabolism reprogrammed for biosynthesis of persistent blue fluorescent tetrapyrroles.
Bottom Line: Amazingly, in the leaves of banana plants, persistent hmFCCs were identified that accounted for about 80 % of the chlorophyll broken down, and yellow leaves of M. acuminata display a strong blue luminescence.The structures of eight hmFCCs from banana leaves were analyzed by spectroscopic means.As expressed earlier in related studies, the present findings call for attention, as to still elusive biological roles of these linear tetrapyrroles.
Affiliation: Institute of Organic Chemistry & Center for Molecular Biosciences, University of Innsbruck, 6020 Innsbruck (Austria).Show MeSH
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Mentions: In senescentM. acuminataleaves FCCs accumulate, and NCCs are not found: Indeed, as was shown here, the structures of the leaf hmFCCs differ characteristically from those in the peels of banana fruit, a result, apparently, from processes that occur at the stage of the FCCs. In senescent banana leaves, hypermodified FCCs (hmFCCs) accumulate and their amounts come up to as much as about 80 % of the degraded chlorophylls. Thus, hmFCCs are, by far, the major product from chlorophyll breakdown, and they induce senescent M. acuminata leaves to fluoresce blue (Figure 10). Remarkably, the formation of NCCs appears to be completely inhibited due to efficient esterification of FCCs, and formation of the persistent hmFCCs.
Affiliation: Institute of Organic Chemistry & Center for Molecular Biosciences, University of Innsbruck, 6020 Innsbruck (Austria).