Identify and characterize SNP markers for the candidate genes HKT1;5 and SOS1 in 18 Date palm cultivars. Technical Report

Abstract

The present study is prepared within the framework of the Development of Sustainable Date Palm Production Systems in Gulf Cooperation Council Countries project. This research and development project aims to produce new knowledge and practices to improve date palm production systems in the Gulf region. The main activities of the project include improving the productivity of cultivars, managing natural resources (land and water) for optimal performance, optimizing the use of different inputs in the cropping process (fertilizers, pollinators, wastewater, etc.), and studying the genetic diversity of date palms. As significant gains have been made in characterizing the genetic mechanisms underlying the response to abiotic stress (Seki et al. 2003; Wang et al. 2000; Zhu, 2003; Hu et al. 2006). These include the identification of genes and pathways responsible for variation in salinity tolerance in plants. Ion transporters and their localization in key cell types underpin plant salinity tolerance. Root xylem parenchyma cells represent the minimizing entry cell types for shoot sodium exclusion as they have a physical location and unique protein primed for this role (Henderson & Gilliham, 2015). Introgression of the Triticum monococcum HKT1;5- A into durum wheat improved shoot Na+ exclusion and improved grain yield in the field by 25% (Munns et al., 2012). Other salt tolerance factors expressed in the root stele include the salt overly sensitive (SOS) pathway genes. The plasma membrane Na+/H+ antiporter SOS1 gene functions to expel Na+ ions out of the cell in exchange for H+ ions. SOS1 regulates sodium efflux in roots and the long-distance transport of sodium from roots to shoots. Sodium extrusion in root epidermal cells is a mechanism that may contribute to salinity tolerance in date palm. HKT1;5 gene is responsible for maintaining high cytosolic K+/Na+ ratio and reduces Na+ load to the xylem before entering the shoot, A first comprehensive catalogue of ~12 million common single nucleotide polymorphisms (SNPs) based on whole genome re-sequencing of 62 date palm varieties originated from North Africa to Middle East, as well as newer production areas in Pakistan, was accomplished by New York University, Abu Dhabi. The objective is to produce a SNP genotyping array capable of rapidly determining the genotype at 100,000 SNP loci from a single date palm sample. Develop a high-density SNP genotyping array will allow to discriminate alleles at individual genomic positions using isothermal probes.