Expression profiling of TaARGOS homoeologous drought responsive genes in bread wheat

Kashif Ahmed,Ghulam Shabbir,Maqsood Qamar,Mukhtar Ahmed,Atta Mohi Ud Din,Nazia Rehman,Sabahat Noor

doi:10.1038/s41598-022-07637-y

Abstract

Drought tolerant germplasm is needed to increase crop production, since water scarcity is a critical bottleneck in crop productivity worldwide. Auxin Regulated Gene involved in Organ Size (ARGOS) is a large protein family of transcription factors that plays a vital role in organ size, plant growth, development, and abiotic stress responses in plants. Although, the ARGOS gene family has been discovered and functionalized in a variety of crop plants, but a comprehensive and systematic investigation of ARGOS genes in locally used commercial wheat cultivars is still yet to be reported. The relative expression of three highly conserved TaARGOS homoeologous genes (TaARGOS-A, TaARGOS-B, TaARGOS-D) was studied in three drought-tolerant (Pakistan-2013, NARC-2009 and NR-499) and three sensitive (Borlaug-2016, NR-514 and NR-516) wheat genotypes under osmotic stress, induced by PEG-6000 at 0 (exogenous control), 2, 4, 6, and 12 h. The normalization of target genes was done using β-actin as endogenous control, whereas DREB3, as a marker gene was also transcribed, reinforcing the prevalence of dehydration in all stress treatments. Real-time quantitative PCR revealed that osmotic stress induced expression of the three TaARGOS transcripts in different wheat seedlings at distinct timepoints. Overall, all genes exhibited significantly higher expression in the drought-tolerant genotypes as compared to the sensitive ones. For instance, the expression profile of TaARGOS-A and TaARGOS-D showed more than threefold increase at 2 h and six to sevenfold increase after 4 h of osmotic stress. However, after 6 h of osmotic stress these genes started to downregulate, and the lowest gene expression was noticed after 12 h of osmotic stress. Among all the homoeologous genes, TaARGOS-D, in particular, had a more significant influence on controlling plant growth and drought tolerance as it showed the highest expression. Altogether, TaARGOSs are involved in seedling establishment and overall plant growth. In addition, the tolerant group of genotypes had a much greater relative fold expression than the sensitive genotypes. Ultimately, Pakistan-2013 showed the highest relative expression of the studied genes than other genotypes which shows its proficiency to mitigate osmotic stress. Therefore, it could be cultivated in arid and semi-arid regions under moisture-deficient regimes. These findings advocated the molecular mechanism and regulatory roles of TaARGOS genes in plant growth and osmotic stress tolerance in contrasting groups of wheat genotypes, accompanied by the genetic nature of identified genotypes in terms of their potential for drought tolerance.

Highlights

Increasing crop productivity has been the main objective of the breeding program due to an upsurge in the demand and use of agricultural commodities for feed, food, and fuel, following substantial growth in the global population and emerging e conomies[1–4]
The founding member of the ORGAN SIZE RELATED (OSR) homologs, AUXIN REGULATED GENE INVOLVED IN ORGAN SIZE (ARGOS), has been identified in Arabidopsis as an auxin-induced gene that is transcribed in growing organs
The maize plant organ growth and yield are progressed by the overexpression of ZmARGOS120, while abiotic stress has been linked to ARGOSs in maize crop[18,19]

Summary

Introduction

Increasing crop productivity has been the main objective of the breeding program due to an upsurge in the demand and use of agricultural commodities for feed, food, and fuel, following substantial growth in the global population and emerging e conomies[1–4]. The quantitative expression patterns of TaARGOS homoeologous genes in inevitable drought tolerant and sensitive bread wheat genotypes were quantified to determine the resilience pathway against PEG-induced dehydration and response of studied genes at various time points. In drought-tolerant wheat genotypes (NR-499, NARC-2009, and Pakistan-2013), the expression of the DREB3 gene was incline significantly at 2 h (> fourfold), peaked at 4 h (6–7 folds) and started to decline after 6 h of moisture stress (Fig. 1).

Results

Conclusion