Ectopic Expression of an Atypical Hydrophobic Group 5 LEA Protein from Wild Peanut, Arachis diogoi Confers Abiotic Stress Tolerance in Tobacco

Abstract

Late embryogenesis abundant (LEA) proteins are a group of hydrophilic proteins, which accumulate in plants under varied stress conditions like drought, salinity, extreme temperatures and oxidative stress suggesting their role in the protection of plants against these stresses. A transcript derived fragment (TDF) corresponding to LEA gene, which got differentially expressed in wild peanut, Arachis diogoi against the late leaf spot pathogen, Phaeoisariopsis personata was used in this study. We have cloned its full length cDNA by RACE-PCR, which was designated as AdLEA. AdLEA belongs to the atypical Group 5C of LEA protein family as confirmed by sequence analysis. Group 5C LEA protein subfamily contains Pfam LEA_2 domain and is highly hydrophobic. In native conditions, expression of AdLEA was upregulated considerably upon hormonal and abiotic stress treatments emphasizing its role in abiotic stress tolerance. Subcellular localization studies showed that AdLEA protein is distributed in both nucleus and cytosol. Ectopic expression of AdLEA in tobacco resulted in enhanced tolerance of plants to dehydration, salinity and oxidative stress with the transgenic plants showing higher chlorophyll content and reduced lipid peroxidation as compared to wild type plants. Overexpressed AdLEA tobacco plants maintained better photosynthetic efficiency under drought conditions as demonstrated by chlorophyll fluorescence measurements. These plants showed enhanced transcript accumulation of some stress-responsive genes. Our study also elucidates that ROS levels were significantly reduced in leaves and stomatal guard cells of transgenic plants upon stress treatments. These results suggest that AdLEA confers multiple stress tolerance to plants, which make it a potential gene for genetic modification in plants.

Selection of Reference Genes for qRT-PCR Analysis of Gene Expression in Stipa grandis during Environmental Stresses

“…grandis defense against stressful conditions. The late embryogenesis abundant protein encoding gene LEA has been widely reported to participate in responses to drought, cold, and salt stresses, and ABA treatment, and plays an important role in plant tolerance to abiotic stress [47–51]. The significantly increased expression of SgLEA under drought, cold, salt, high pH and ABA treatments (Fig 5A–5E) implies that SgLEA participates in S .…”

A LEA Gene from a Vietnamese Maize Landrace Can Enhance the Drought Tolerance of Transgenic Maize and Tobacco

“…Functional analysis of 5C LEA proteins showed that the molecular mechanisms of the protective ability against desiccation stress were diverse. The overexpression of AdLEA, a 5C LEA protein from wild peanut, could help maintain the photosynthetic efficiency, reduce the ROS level, and induce the expression of some drought-responsive genes in transgenic tobacco [26]. Meanwhile, overexpressing SiLEA14 from foxtail millet enhanced a higher level of proline and sugar accumulation in transgenic Arabidopsis [13].…”

“…A small number of group 5C LEA proteins have been characterized, but their physical characteristics and biological functions are largely unknown. Some members of group 5C were identified in other plants such as cotton LEA14A, soybean D95-4, tomato ER5, hot pepper CaLEA6, Arabidopsis AtLEA14A, sweet potato IbLEA14A, rice OSLEA5, foxtail millet SiLEA14A, and wild peanut LEA [8,13,[20][21][22][23][24][25][26]. The expression of LEA 5C proteins is upregulated by ABA and multiple abiotic stresses including salt and drought [13,23].…”

Metabolic Profiling to Elucidate Genetic Elements Due to Salt Stress

“…Despite of many research efforts to gain a better understanding of the mechanisms adopted by plants to cope or avoid salt stress, mechanisms of salt tolerance in plants, especially at genetic level are not yet fully understood. However, several studies have indicated that salt stress induces the expression of many specific metabolites and their modifications . Therefore, in this review article, we have presented certain representative classes of metabolites, their genetic basis, and the underlying genes that control these metabolites which ultimately help plants to survive during the salt stress.…”

“…However, several studies have indicated that salt stress induces the expression of many specific metabolites and their modifications. [10][11][12][13] Therefore, in this review article, we have presented certain representative classes of metabolites, their genetic basis, and the underlying genes that control these metabolites which ultimately help plants to survive during the salt stress. Furthermore, by combining all the available literature the deficiencies in the current research are highlighted along with the postulation of a stronger and successful integrated approach for crop plants to combat salt stress.…”