Overexpression of Arabidopsis AnnAt8 Alleviates Abiotic Stress in Transgenic Arabidopsis and Tobacco

Abstract

Abiotic stress results in massive loss of crop productivity throughout the world. Because of our limited knowledge of the plant defense mechanisms, it is very difficult to exploit the plant genetic resources for manipulation of traits that could benefit multiple stress tolerance in plants. To achieve this, we need a deeper understanding of the plant gene regulatory mechanisms involved in stress responses. Understanding the roles of different members of plant gene families involved in different stress responses, would be a step in this direction. Arabidopsis, which served as a model system for the plant research, is also the most suitable system for the functional characterization of plant gene families. Annexin family in Arabidopsis also is one gene family which has not been fully explored. Eight annexin genes have been reported in the genome of Arabidopsis thaliana. Expression studies of different Arabidopsis annexins revealed their differential regulation under various abiotic stress conditions. AnnAt8 (At5g12380), a member of this family has been shown to exhibit ~433 and ~175 fold increase in transcript levels under NaCl and dehydration stress respectively. To characterize Annexin8 (AnnAt8) further, we have generated transgenic Arabidopsis and tobacco plants constitutively expressing AnnAt8, which were evaluated under different abiotic stress conditions. AnnAt8 overexpressing transgenic plants exhibited higher seed germination rates, better plant growth, and higher chlorophyll retention when compared to wild type plants under abiotic stress treatments. Under stress conditions transgenic plants showed comparatively higher levels of proline and lower levels of malondialdehyde compared to the wild-type plants. Real-Time PCR analyses revealed that the expression of several stress-regulated genes was altered in AnnAt8 over-expressing transgenic tobacco plants, and the enhanced tolerance exhibited by the transgenic plants can be correlated with altered expressions of these stress-regulated genes. Our findings suggest a role for AnnAt8 in enhancing abiotic stress tolerance at different stages of plant growth and development.

Comparative Lipidomics and Proteomics of Lipid Droplets in the Mesocarp and Seed Tissues of Chinese Tallow (Triadica sebifera)

“…Annexin was also identified only in the seed LD. Its orthologous gene in A. thaliana, AnnAt8 (At5g12380), was shown to exhibit hundreds-fold increases in transcription levels under dehydration and salt stress (Yadav et al, 2016 ). Its overexpression in Arabidopsis and tobacco plants resulted in higher rates of seed germination, better plant growth, and higher chlorophyll retention than wild type plants under abiotic stress treatments (Yadav et al, 2016 ).…”

Comprehensive analyses of the annexin (ANN) gene family in Brassica rapa, Brassica oleracea and Brassica napus reveals their roles in stress response

“…The variable N-terminal region interacts with other proteins and is responsible for the functional diversity of ANN 4 .Recent studies have identified the ANN gene family in Arabidopsis thaliana (8 genes), Brassica rapa (13), Solanum lycopersicum (9), Solanum tuberosum (9), Oryza sativa (10), Triticum aestivum (25), Gossypium raimondii (14), Arachis hypogaea L. (8), Hordeum vulgare (11), Medicago truncatula (10), Populus trichocarpa (12), Vitis vinifera (14), Carica papaya (12), Glycine max (22), Cochliobolus sativus (11), Sorghum bicolor (10), Zea mays (12), Brachypodium distachyon (11), Selaginella mollendorffii (5), and Physcomitrella patens (7) via genome-wide analysis 2,5-11 .Studies have shown that ANN gene family plays a significant role in plant development and plant protection during both abiotic and biotic stresses 1,3,12,13 . In Arabidopsis, two ANN genes (AtANN1 and AtANN4) were regulated by abiotic stress, negatively regulated plant tolerance to drought, salinity, and heat stress, while AtANN8 was open Scientific RepoRtS | (2020) 10:4295 | https://doi.org/10.1038/s41598-020-59953-w www.nature.com/scientificreports www.nature.com/scientificreports/ positive regulated the plant abiotic tolerance [14][15][16][17][18][19][20][21] . Studies also demonstrated that AtANN1 and AtANN2 regulated root growth and development [20][21][22] .…”

“…Studies have shown that ANN gene family plays a significant role in plant development and plant protection during both abiotic and biotic stresses 1,3,12,13 . In Arabidopsis, two ANN genes (AtANN1 and AtANN4) were regulated by abiotic stress, negatively regulated plant tolerance to drought, salinity, and heat stress, while AtANN8 was open Scientific RepoRtS | (2020) 10:4295 | https://doi.org/10.1038/s41598-020-59953-w www.nature.com/scientificreports www.nature.com/scientificreports/ positive regulated the plant abiotic tolerance [14][15][16][17][18][19][20][21] . Studies also demonstrated that AtANN1 and AtANN2 regulated root growth and development [20][21][22] .…”

Characterization of proteinase inhibitor-II gene under OsRGLP2promoter for salt stress in transgenic Nicotiana benthamiana

“…However, TL1, TL2, and TL3 displayed 63%, 73%, and 77% reduction in chlorophyll content, respectively ( Figure 6). In a recent study, Yadav et al (2016) developed transgenic tobacco plants overexpressing the Arabidopsis annexin gene (AnnAt8) and demonstrated higher chlorophyll retention in transgenic plants than the WT after treatment with 300 mM and 400 mM NaCl. Tan et al (2015) also demonstrated higher chlorophyll content in transgenic Arabidopsis plants overexpressing a novel cystatin gene from Malus prunifolia (MpCYS5) when compared with the WT in the presence of 200 mM NaCl.…”