In multicellular organisms, the exchange of information via signaling within the cell and between cells can stimulate the recognition of biotic and abiotic factors so that the plant system can respond to the stresses and regulate growth and development. The growth and the genetic potential of a plant are affected by a variety of environmental factors such as light, temperature, humidity, moisture, lodging, and wind velocity, and internal plant atmosphere which includes plant hormone, signaling molecules, chlorophyll content, and stomatal movement (Fulgosi et al., 2002). There are small molecular proteins called 14-3-3 proteins in plant cells that play an important role in cell signal transduction in response to biotic and abiotic stresses, and regulation of plant growth and development (Etienne et al., 2015). In addition, also participates in the material transport and metabolism during various metabolic processes, and plant hormone signaling. These signaling proteins interact with plant defense protein factors, and kinase activation, also plays important role in the inhibition of cell division and differentiation and oil transport proteins. The 14-3-3 proteins which are phosphorylation-dependent or phosphorylation-independent binding protein family also stimulate gibberellin transcription protein (GASA) etc. (Eleanor et al., 2011; Monica et al., 1996; Boutrot et al., 2008; Herzog et al., 1995).
Originally 14-3-3 proteins were found in human brain tissue which was isolated from bovine acidic soluble proteins (Moore and Perez, 1967). The name of 14-3-3 proteins originated from the phase chromatography using diethylaminoethyl cellulose (DEAE) fractions elution in the position of fragments and starch migration rate in the gel electrophoresis. Further, the studies on 14-3-3 proteins demonstrated that these proteins are highly conserved in eukaryotes which formed heterologous or homologous dimeric molecules with monomeric protein molecules. The 14-3-3 proteins were extensively studied in Arabidopsis and are also known as (GF14s) or General regulatory factors (GRFs) (Rooney & Ferl, 1995; Wu, Rooney, & Ferl, 1997). The varying number of 14-3-3 genes are identified in genomes of different plant species for example 10 in Arabidopsis, and 18 in soybean which is polyploid plant species (Li & Dhaubhadel, 2011; Wu et al., 1997)
The 14-3-3 interacts with target proteins through a specific phosphorylation site resulting in protein and protein interactions and regulating signal transduction (Paul et al., 2012). In plants there are more than 300 target proteins were identified to interact with 14-3-3 protein (Oecking et al., 2009). These target proteins are involved in a variety of important physiological processes during abiotic and biotic stress tolerance, activity and stability confirmation of proteins, protein localization, and transport and regulation of cell division (Yang et al. 2014). There are several reports on the expression and functional diversity of H+-ATPase membrane proteins. The 14-3-3 protein is involved in the regulation of the activity of H+-ATPase (Geoffrey et al., 2008). Nitrate reductase is a key to the nitrate metabolic enzyme the activity of nitrate reductase is dependent on the process of phosphorylation. In the dark condition, 14-3-3 protein inhibits the activity of nitrate reductase and reduces the production and metabolism of toxic nitrate (Bachmann et al. 1996). Sucrose phosphate synthase is a key enzyme of carbon metabolism in plants, the 14-3-3 can inhibit the activity of sucrose phosphate synthase, on the other hand, with the inhibition of 14-3-3 activity the corresponding starch and sucrose content increases (Moorhead et al., 1999; Toroser et al., 2000). In barley, 14-3-3 protein interacts with transcription factors such as AREB ABF/ABI5, involved in abscisic acid (ABA) metabolism. The VP1 gene mutations in ABI5 cannot be combined without 14-3-3 proteins, studies reported that binding VP1 and ABI5 needs 14-3-3 as a bridge to form a complex binding to the ABA-responsive element (Himmelbach et al., 2003). The 14-3-3 negatively regulates the BRZ1 and BRZ2 / BES1 transcription in Arabidopsis thaliana and rice (Bai et al., 2007; Gampala et al., 2007). The 14-3-3 protein is also involved in the signaling of brassinosteroids (Wang et al., 2011) and gibberellins (Ishida et al. 2004) signaling, a photographic approach (Taoka et al., 2011). Plant 14-3-3 proteins and target protein binding during the stress response stimulate signaling mechanism in transgenic plants which includes the non-biological response of ROS reaction, salt stress tolerance, osmotic stress tolerance, high and low-temperature stress response (Chen et al., 1994; Kidou et al., 1993; Roberts et al., 2002; Elmayan et al., 2007). In addition, the biological response of plant resistance genes (R-genes) in response to pathogen attack (Yang et al., 2009). Peanut is an important oilseed crop and legume crop, majority of the research efforts in peanut are carried out to improve the resistance against devastating biotic stresses such as stem rot (Dodia et al. 2019), late leaf spot (2020), and bacterial wilt (Luo et al. 2019). Around 90% of peanut is cultivated in semi-arid zones of the world where drought has become an important yield-limiting factor (Gangurde et al. 2019; Pandey et al. 2021). As discussed above, several reports have revealed that the 14-3-3 gene involves the regulation of growth and development and stimulation of responses against biotic and abiotic stresses in plants. Therefore, it is necessary to perform the structural and functional analysis of the peanut 14-3-3 gene, so that it can be used as a molecular tool to improve the peanut varieties resistant to biotic and abiotic stresses. In this context, in the present study, 22 14-3-3 genes, named AhGRFs, were identified through a genome-wide identification approach. Among identified genes, AhGRFi was cloned and transformed in Arabidopsis thaliana to analyze its structure and function peanut. Sequence similarity of the peanut 14-3-3 protein was investigated, and the expression pattern of the 14-3-3 genes in different plant tissues of peanut during different developmental stages was studied. The expression of the 14-3-3 gene was validated using quantitative real-time quantitative PCR.