The effect of water deficit and excess copper on proline metabolism in Nicotiana benthamiana

Abstract

Fluctuation in proline content is a widespread phenomenon among plants in response to heavy metal stress. To distinguish between the participation of water deficit and copper on changes in proline metabolism, potted plants and floating leaf discs of tobacco were subjected to CuSO4 treatments. The application of copper increased the proline content in the leaves concomitantly with decreased leaf relative water content and increased abscisic acid (ABA) content in the potted plant. Excess copper increased the expression of two proline synthesis genes, pyrroline-5-carboxylate synthetase (P5CS) and ornithine aminotransferase (OAT) and suppressed proline catabolism gene, proline dehydrogenase (PDH). However, in the experiment with tobacco leaf discs floating on CuSO4 solutions, the excess copper decreased proline content and suppressed the expression of the P5CS, OAT and PDH genes. Therefore, proline accumulation in the potted tobacco plants treated with excess Cu treatment might not be the consequence of the increased copper content in tobacco leaves but rather by the accompanied decrease in water content and/or increased ABA content

Interactions between nitrogen nutrition and phytohormone levels in Festulolium plants

“…The lower reductions of ABA concentrations 3 and 5 days after fertilization were observed after ammonium nitrogen application, mainly after injection application. Abscisic acid is thought to play an important role in proline accumulation (Ku et al 2012). Our results are in agreement with this observation.…”

The Effect of Calcium Chloride on Growth, Photosynthesis, and Antioxidant Responses of Zoysia japonica under Drought Conditions

“…Free proline accumulation in the leaves under stress conditions is of utmost importance for plant adaptation during stress [48,49]. Our data suggests that proline content increased in zoysiagrass for all pretreatments under drought (Figure 7B).…”

Exogenous hydrogen peroxide increases dry matter production, mineral content and level of osmotic solutes in young maize leaves and alleviates deleterious effects of copper stress

“…The increased proline content in maize cultivars exposed to copper stress may be associated with the response to water deficit. Indeed, excess Cu-induced accumulation of proline has been recorded in various plants such as Oryza sativa (Chen et al, 2001 ) and Nicotiana benthamiana (Ku et al, 2012 ). We also observed that proline accumulation was high in the plants treated with H 2 O 2 in two maize cultivars.…”

“…Similarly, proline content increased in plants when exposed to wide variety of environmental stresses and thus provided the plants protection against damage by reactive oxygen species (Aspinall and Paleg, 1981 ). For instance, excess copper induced accumulation of proline in various plants such as Oryza sativa (Chen et al, 2001 ) and Nicotiana benthamiana (Ku et al, 2012 ). Adversely, it has been shown a decrease in soluble protein level at several stress condition like copper and aluminum stresses (Yadav et al, 2009 ).…”