Genome-wide identification of WRKY genes and their expression profiles under different abiotic stresses in Elaeis guineensis

Abstract

African oil palm (Elaeis guineensis) is an important oil crop grown in tropical region and sensitive to low temperature along with high tolerance to salt and drought stresses. Since the WRKY transcription factor family plays central roles in the regulation of plant stress tolerance, 95 genes belonging to the WRKY family were identified and characterized in oil palm genome. Gene structure analysis showed that EgWRKY genes have considerable variation in intron number (0 to 12) and gene length (477bp to 89,167 bp). Duplicated genes identification indicated 32 EgWRKY genes originated from segmental duplication and two from tandem duplication. Based on transcriptome data, most EgWRKY genes showed tissue-specific expression patterns and their expression could be induced under cold stress. Furthermore, six EgWRKY genes with more than two-folded increased expression level under cold stress were validated by RT-qPCR, which has higher expression level in cold, drought and high salinity treatment. The identification and characterization of WRKY gene family showed that EgWRKY were associated with a wide range of abiotic stress responses in Elaeis guineensis and some EgWRKY members with high expression levels could be selected for further research in analyzing their functions in the stress response in African oil palm.

Transgenic Breeding Approaches for Improving Abiotic Stress Tolerance: Recent Progress and Future Perspectives

“…There is a crucial need for efficient crop improvement strategies with novel genome editing techniques, such as CRISPR-Cas9 [69], which is easy, fast, efficient, and accurate in obtaining new genome edited crops ( Figure 5). Global warming is leading to increases in several kinds of abiotic stress, including temperature and drought, which are major abiotic stresses that limit crop production [70]. Scientists are screening to determine candidate genes using CRISPR-Cas9 technology to overcome these environmental problems.…”

“…When considering tropical climates, Elaeis guineensis is the main source of edible oil in Africa and is very sensitive to low temperature, but resists drought and salinity well [23]. WRKY genes demonstrated tissue-specific expression under low temperature stress in oil palms [70].…”

Seed Germination in Oil Palm (Elaeis guineensis Jacq.): A Review of Metabolic Pathways and Control Mechanisms

“…For example, a WRKY transcription factor that acts as negative regulator of abscissic acid signaling is crucial to up-regulate lipid remobilization during germination in sunflower [ 73 ]. A comprehensive analysis of WRKY factors in oil palm has been provided [ 74 ], and future research will likely provide more insight on differential expression during the germination of WRKY factors associated with abscissic acid and gibberellin signaling. Additionally, mitochondrial reactivation during seed imbibition has been shown to be stimulated by gibberellins and inhibited by abscissic acid in Arabidopsis [ 45 ].…”

Application of CRISPR/Cas9 Genome Editing Technology for the Improvement of Crops Cultivated in Tropical Climates: Recent Progress, Prospects, and Challenges

“…It was found that EgWRKY genes of oil palm had showed tissue-specific expression patterns with higher levels under cold stress. It is now well recognized that almost all the EgWRKY genes are upregulated under abiotic stresses, and the authors suggest that the expression of EgWRKY genes in African oil palm play important roles in the responses to abiotic stresses (Xiao et al, 2017 ). Although CRISPR/Cas9 has not yet been applied for the improvement of most of the tropical crops, opportunity does exist to apply the technology for genetic modification of numerous tropical crops to increase yield and improve product quality, abiotic stress tolerance, and enhancing the resistance to destructive diseases and pests.…”