The AKR gene family and modifying sex ratios in palms through abiotic stress responsiveness

Abstract

Sex ratio (SR), the ratio of female inflorescences to total inflorescences, is one of the main yield components of oil palm (Elaeis guineensis Jacq). The SR quantitative trait locus (QTL) was recently identified on linkage (LG) 8 with a phenotype variance explained (PVE) of 11.3 %. The use of both genetic and physical mapping is one strategy for uncovering the genetic basis of the traits. Here, we report the construction of bacterial artificial chromosome (BAC) and fosmid libraries, and their use for physical mapping in oil palm. Combined, the libraries consist of more than 200,000 clones, representing 6.35 genome equivalents. Physical mapping at the SR locus was implemented by incorporating the published oil palm genome sequence and positive BAC/fosmid clones as identified by colony PCR screening. Based on the previously published sequences, the interval (about 184 kb) was comprised of 19 contigs of the known sequences (~117 kb, 64 %). After, combining the 454 pyrosequences of 15 positive clones and the previously published sequences, the known sequences were revealed to cover about 82 % of the interval (~150 kb), and were used for identifying the new markers by designing 35 gene-based and 23 simple sequence repeat (SSR)-amplified primers. As a result, a putative aldo-keto reductase gene (named EgAKR1) was revealed to be a promising candidate for sex ratio determination, via controlling female inflorescence number (11 % of PVE). This was predicted from the two newly identified polymorphic marker loci (mEgSSRsr8-21LB and mEgAKR1-9) designing from EgAKR1. The functions of AKR gene families in other plant species and our promoter analysis suggested that EgAKR1 may contribute to the sex ratio through abiotic stress responsiveness.

Breeding the oil palm (Elaeis guineensisJacq.) for climate change

“…Indeed, Somyong et al (2014Somyong et al ( , 2015 described a putative aldo-keto reductase gene (named EgAKR1) which was revealed as a promising candidate for sex ratio determination via the control of female inflorescence number. More recently, Somyong et al (2016) Fig.…”

Genome-Wide Identification and Characterization of Aldo-Keto Reductase (AKR) Gene Family in Response to Abiotic Stresses in Solanum lycopersicum

“…On the basis of expression characteristics, Solyc09g011240.3.1 , Solyc07g043570.3.1 , and Solyc01g106450.3.1 were silenced in tomatoes by the VIGS system, which showed sensitivity to drought and salt stresses with low contents of Pro and POD and high content of MDA at each stress stage ( Figure 10 ). The overexpression of OsAKR4C15 in A. thaliana lines resulted in lower contents of MDA and MG under both stresses and control conditions than wild types [ 32 ]. These results suggested that AKR members of tomatoes were in response to drought and salt stresses and that Solyc09g011240.3.1 , Solyc07g043570.3.1 , and Solyc01g106450.3.1 might play positive roles in regulating the tolerance of tomatoes in drought and salt stresses.…”

The palm family (Arecaceae): a microcosm of sexual system evolution

“…Clearly, it will be of great interest to compare data between different palm species with contrasting sexual systems, including species such as oil palm which display environmentally regulated sex determination (Adam et al ., ). In this context, the recently published oil palm genome (Singh et al ., , b) is an invaluable resource and has already been used to identify a genomic region of importance to sex regulation (Somyong et al ., ). The region in question contains a putative aldo‐keto reductase gene that might be involved in abiotic stress response.…”