Changes in lipid profile during growth and senescence of Catharanthus roseus leaf

Abstract

Various lipid classes and compounds were monitored during the period of leaf emergence to leaf drop of Catharanthus roseus. The expansion to early maturation phase was accompanied by cellular build-up of all major lipid classes, whilst aging and senescence were characterized by their substantial decline, except for the neutral lipids; the leaf monogalactosyl diglyceride/digalactosyl diglyceride ratio decreased from 4.3 (complete maturity) to 2.1 (abscised stage). The early maturation stage was the earliest stage when appreciable amounts of free sterols and fatty acids could be observed. Sterol/phospholipids ratios increased by 68-fold in the abscised leaf as compared to that at full maturity. The unsaturated/saturated fatty acid ratio was far lower in the senescent leaf as compared to that of the fully expanded leaf. The spatial alterations in lipid profiles may be suggestive of concomitant changes in membrane ultrastructure and functions, putatively leading to perturbation of indole alkaloid sequestration capability of the tissues of a species of pharmaceutical significance. Key words: Catharanthus roseus, glycolipids, leaf development, phospholipids, senescence, sterol Alterações no perfil de lipídeos durante o crescimento e a senescência de folhas de Catharanthus roseus: Rastrearamse alterações na composição de vários compostos e classes de lipídeos em folhas de Catharanthus roseus, desde a emergência até a abscisão. Da expansão ao início da maturação da folha, houve incrementos nas concentrações de todas as principais classes de lipídeos, observando-se tendência oposta na senescência, à exceção de lipídeos neutros; a razão monogalactosil diglicerídeo/digalactosil diglicerídeo decresceu de 4.3 (maturidade completa) para 2.1 (abscisão). Quantidades apreciáveis de esteróis e ácidos graxos começaram a ser observadas apenas no início maturação foliar. A razão esteróis/fosofolipídeos aumentou 68 vezes na fase de abscisão em relação à folha em sua completa maturidade. A razão ácidos graxos insaturados/ácidos graxos saturados foi muito menor na folha senescente que na folha jovem completamente expandida. As alterações espaciais no perfil de lipídeos podem ser uma sugestão de alterações concomitantes na função e ultra-estrutura da membrana, acarretando, putativamente, perturbações na capacidade de seqüestro de alcalóides dos tecidos de uma espécie importante, de um ponto de vista farmacêutico.

Salinity induced physiological and biochemical changes in chickpea (Cicer arietinum L.) genotypes

“…Photosynthetic pigments decreased in chickpea grown under salt stress (Beltagi 2008) and photosynthesis was reduced to 60% (Murumkar and Chavan 1993). The inhibitory effects of salt stress on chlorophyll pigments could be due to suppression of specific enzymes responsible for the synthesis of the green pigments, or due to increased chlorophyllase activity in wheat, Catharanthus roseus and mustard respectably (Kiani et al 2005;Mishra et al 2006). Water uptake by plants hence, attains importance under saline conditions.…”

Turnover of Fatty Acids during Natural Senescence of Arabidopsis, Brachypodium, and Switchgrass and in Arabidopsis β-Oxidation Mutants

“…For example, the fatty acid content of tobacco (Nicotiana tabacum) leaves decreased more than 50%, changing from 37 mg g 21 dry weight at 10 weeks to 15 mg g 21 dry weight at 14 weeks (Koiwai et al, 1981). The total fatty acids in Roseus leaves dropped from 245 mg per leaf at day 37 to 135 mg per leaf at day 77 (Mishra et al, 2006). Drought-induced senescence of Arabidopsis (Arabidopsis thaliana) leaves resulted in fatty acids decreasing to 36% of the original 33 mg g 21 dry weight (Gigon et al, 2004).…”

Characterization of Carotenoid-protein Complexes and Gene Expression Analysis Associated with Carotenoid Sequestration in Pigmented Cassava (Manihot Esculenta Crantz) Storage Root

“…These proteins are being investigated by several groups to establish the role of their parallel accumulation with carotenoids [3] and lipids of different types [4,5]. These investigations also include examining chromoplast formation [2,3,6], which specially focus on the Fibrillar type that forms a carotenoid-protein complex (CPC) within supramolecular structures where different carotenoid types are sequestered [2,7,8].…”

“…These investigations also include examining chromoplast formation [2,3,6], which specially focus on the Fibrillar type that forms a carotenoid-protein complex (CPC) within supramolecular structures where different carotenoid types are sequestered [2,7,8]. Most of this information was obtained from green tissues where carotenoid function is well documented in dissipating excess excitation energy by participating in non-photochemical quenching, which is essential in protecting the chloroplasts from photo-oxidative damage [9] and lipid changes that occur during leaf senescence due to interconvertion of chloroplasts into chromoplast [5]. Here we provide information on the characterization of carotenoid-protein complex isolated in cassava storage root that is a non green tissue.…”