Partial suppression of gene encoding proline dehydrogenase enhances plant tolerance to various abiotic stresses

Abstract

The role of gene of proline dehydrogenase (PDH) in the maintenance of stress tolerance was investigated using the model transgenic plants of tobacco (Nicotiana tabacum L.) carrying an antisense sup pressor of PDH gene (a fragment of Arabidopsis PDH gene under the control of cauliflower mosaic virus 35S promoter in antisense orientation) and notable for a low activity of PDH and elevated content of proline. The progeny of transgenic plants belonging to the 5th generation (T 5 ) with partially suppressed PDH activity was more resistant to various types of stress as compared with the control plants of tobacco, cv. Petit Havana SR 1 (SR1). The seedlings of transgenic lines cultured in Petri dishes on agar media supplemented with stress agents were resistant to high NaCl concentrations (200-300 mM) and water deficit simulated by an increased agar content in the medium (14 g/l) as compared to the control seedlings of cv. SR1. Juvenile plants of trans genic lines grown in pots filled with a mixture of vermiculite and perlite also manifested the higher resistance to water deficit and low temperatures (2°C and -2°C) than the control plants. Thus, the partial PDH sup pression correlated with an increase in nonspecific resistance to different types of abiotic stress: salinity, water deficit, and low temperatures. Such transgenic lines of tobacco are promising genetic models for thorough investigation of molecular mechanisms of stress resistance in plants.

Agrobacterium-mediated transformation of sunflower (Helianthus annuus L.) in vitro and in planta using Lba4404 strain harboring binary vector pBi2E with dsRNA-suppressor of proline dehydrogenase gene

“…7). It was similar with data obtained with the antisense construct and dou ble stranded RNA suppressor for tobacco plants [7,10,13]. Since the agrobacterial strain that we used had no effect on the metabolism of proline, significant differences between transgenic plants with dsRNA suppressor of ProDH gene and transformed plants in which T DNA is not integrated indicate partial sup pression of proline dehydrogenase gene of sunflower.…”

“…Several studies have demonstrated a positive corre lation between Pro content and increased tolerance of transgenic plants [5][6][7][8][9][10]. However, participation of L proline in the process of adaptation and stability of transgenic plants is not always obvious, as demon strated by a comparison of the tolerance and Pro con tent in wild species [3,11].…”

“…As for the ProDH gene, its role and use fulness of in biotechnology to improve plant resistance to stress is the subject of research. Information on this matter for sense and antisense strategies is available for a limited number of plants [5,7,10,11]. The results of research for different stressors are not always clear [5,11].…”

Metabolic and molecular-genetic regulation of proline signaling and itscross-talk with major effectors mediates abiotic stress tolerance in plants

“…In ABA-hypersensitive prl1 and brassinosteroiddeficient det2 mutants, enhanced Pro accumulation and P5CS1 induction have been recorded. The prl1 mutation reduces the basal level of PDH expression, whereas the det2 mutation increases the inhibitory effect of ABA over PDH (Abraham et al, 2003;Ibragimova et al, 2012). Application of 50 µM ABA to Arabidopsis wild-type, ABA-deficient aba1-1 mutant, and ABA-insensitive abi1-1 and abi1-2 mutant seedlings triggered the expression of AtP5CS and not AtP5CR.…”

Transgenic plants as genetic models for studying functions of plant genes

“…(b) Proline contents in transformant leaves. (c) Transgenic plants were characterized by elevated tolerance to drought, cold, and toxic salts of heavy metals (Kochetov et al, 2004;Kolodyazhnaya et al, 2006;Ibragimova et al, 2012).…”