Genetic engineering of chickpea (Cicer arietinum L.) with the P5CSF129A gene for osmoregulation with implications on drought tolerance

Abstract

Abiotic stresses including water deficit severely limits crop yields in the semi-arid tropics. In chickpea, annual losses of over 3.7 million tones have been estimated to be due to water deficit conditions alone. Therefore, major efforts are needed to improve its tolerance to water deficit, and genetic engineering approaches provide an increasing hope for this possibility. We have used transgenic technology for the introduction of an osmoregulatory gene P5CSF129A encoding the mutagenized D 1-pyrroline-5-carboxylate synthetase (P5CS) for the overproduction of proline. A total of 49 transgenic events of chickpea were produced with the 35S:P5CSF129A gene through Agrobacterium tumefaciens-mediated gene transfer through the use of axillary meristem explants. Eleven transgenic events that accumulated high proline (2-6 folds) were further evaluated in greenhouse experiments based on their transpiration efficiency (TE), photosynthetic activity, stomatal conductance, and root length under water stress. Almost all the transgenic events showed a decline in transpiration at lower values of the fraction of transpirable soil water (dryer soil), and extracted more water than their untransformed parents. The accumulation of proline in the selected events was more pronounced that increased significantly in the leaves when exposed to water stress. However, the overexpression of P5CSF129A gene resulted only in a modest increase in TE, thereby indicating that the enhanced proline had little bearing on the components of yield architecture that are significant in overcoming the negative effects of drought stress in chickpea.

Transgene Pyramiding of theHVA1andmtlDin T3 Maize (Zea maysL.) Plants Confers Drought and Salt Tolerance, along with an Increase in Crop Biomass

“…Mannitol is one of the plant osmoprotectants. An early report by Sheveleva et al [27] indicated that an increase in mannitol accumulation in tobacco (Nicotiana tobacum) and in chickpea (Cicer arietinum L.) tissues caused accumulation of proline, an amino acid needed to balance carbon nitrogen under stress conditions, resulting in improved yield [28]. It has also been reported that expression of certain osmoprotectant pathways improves tolerance to water deficit in wheat (Triticum aestivum), soybean (Glycine max) [29,30], and rice (Oryza sativa) [31].…”

Isolation and characterization of a Δ1-pyrroline-5-carboxylate synthetase (NtP5CS) from Nitraria tangutorum Bobr. and functional comparison with its Arabidopsis homologue

“…Free Pro accumulates in response to stresses such as high salinity [7], water deficit [8], extreme temperature [9], heavy metal toxicity [10,11] and nutrient deficiency [12]. Increased Pro levels and enhanced tolerance to diverse stresses have been observed in transgenic plants overexpressing P5CS genes, including rice [13,14], wheat [15], potato [16], tobacco [17], citrus [18] and chickpea [19,20].…”

Molecular and Physiological Analysis of Drought Stress in Arabidopsis Reveals Early Responses Leading to Acclimation in Plant Growth

“…PHENOPSIS has been developed as an automated controlled drought screen, which was used to compare the performance of different Arabidopsis ecotypes (accessions) and resulted in the identification of a resistant accession, An1 . Controlled drought was also used to study the response of the Arabidopsis erecta mutant and ERECTA gene complementation (Masle et al, 2005), the overexpression of the Arabidopsis ESKIMO1 gene (Bouchabke-Coussa et al, 2008), and overexpression of the Pro biosynthesis gene in chickpea (Cicer arietinum;Bhatnagar-Mathur et al, 2009).…”