Chill-induced changes in fatty acid composition of tonoplast vesicles from hypocotyls of Vigna unguiculata (L.) Walp.

Abstract

The present study was undertaken to investigate the changes induced by chilling on fatty acid composition of tonoplast vesicles from hypocotyls of Vigna unguiculata (L.) Walp. The 7 day-old control seedlings were grown at 25°C while treated seedlings were submitted to low temperatures (10°C and 4°C) for 4 days after 3 days germination. The chilling stress resulted in a differential inhibition of plant growth at 10°C and 4°C. Following chilling at 10°C and 4°C, the rate of unsaturated to saturated fatty acids increased under chilling stress. Our results suggest that the increase of unsaturated fatty acids content as well as the higher rate unsaturated/saturate fatty acids might be used by V. unguiculata plants as an adaptation mechanism likely to maintain the vacuolar membrane fluidity under low temperatures.Key words: chilling, cowpea, lipid, fatty acids, membrane, vacuole. resuMoO presente trabalho analisa as mudanças na composição de ácidos graxos de vesículas de tonoplato de hipocótilos de Vigna unguiculata (L.) Walp induzida por estresse causado por baixas temperaturas. Plântulas em condição controle desenvolveram-se por 7 dias à temperatura de 25°C e as plântulas tratadas foram submetidas a 10 ou 4°C por 4 dias, 3 dias após a germinação a 25°C. O frio (10 ou 4°C) induziu um efeito inibitório no desenvolvimento das plântulas e esse efeito foi mais pronunciado a 4°C. Além disso, o grau de insaturação dos ácidos graxos nas vesículas de tonoplasto aumentou sob o efeito do frio, o que pode indicar um aumento da permeabilidade das vesículas da membrana vacuolar. Nossos resultados sugerem que plantas de V. unguiculata aumentaram o seu conteúdo de ácidos graxos insaturados bem como a razão entre ácidos graxos insaturados/saturados, como mecanismo de adaptação ao frio numa tentativa de manter a fluidez da membrana vacuolar.

Mutualistic association of Paecilomyces formosus LHL10 offers thermotolerance to Cucumis sativus

“…However, in 38°C condition, we observed low electrolytic leakage, consistent with the decrease in linolenic and linoleic. Rydlová et al (2011), also observed similar results in the association of flex plants with plant growth promoting Glomus species, while Oliveira et al (2010) found same results under chilling stress. Similar results have been observed in other species (Murakami et al 2000;Grover et al 2000;Guerzoni et al 2001;Falcone et al 2004).…”

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Changes in the nature of phenolic deposits after re-warming as a result of melatonin pre-sowing treatment of Vigna radiata seeds

“…A similar effect was observed in V. radiata (L.) Wilczek and Vigna unguiculata (L.) Walp. seedlings (Posmyk and Janas, 2007;Oliveira et al, 2010). However, in our study, this effect was reversible after 2 days of re-warming, especially in H-MEL roots, where H-MEL treatment caused a 20% increase in root length relative to C treatment (Table 1).…”

Exophiala sp.LHL08 association gives heat stress tolerance by avoiding oxidative damage to cucumber plants

“…These scavengers stabilizes subcellular structures and buffers cellular redox potential under stress conditions (Wahid et al 2007;Zinn et al 2010), while their activity depends on the level of stress perception by plants. The structural and functional stability of membrane is essential for plant's resistance to temperature stress, while damage in membrane structure can affect the permeability and the activity of membrane-localized enzymes Ruelland and Zachowski 2010;Oliveira et al 2010). Since membrane bounded lipid hydroperoxides are difficult to measure due to their instability, we often rely on the degree of lipid peroxidation by quantifying the secondary breakdown products like MDA.…”