Transcriptome profiling of differentially expressed genes in cytoplasmic male-sterile line and its fertility restorer line in pigeon pea (Cajanus cajan L.)

Swati Saxena,N K Singh,Sandhya Sanand,Tanvi Kaila,Kishor Gaikwad,Pavan K Chaduvla,Sarika Sahu,A R Rao,Deepti Nigam

doi:10.1186/s12870-020-2284-y

Abstract

BackgroundPigeon pea (Cajanus cajan L.) is the sixth major legume crop widely cultivated in the Indian sub-continent, Africa, and South-east Asia. Cytoplasmic male-sterility (CMS) is the incompetence of flowering plants to produce viable pollens during anther development. CMS has been extensively utilized for commercial hybrid seeds production in pigeon pea. However, the molecular basis governing CMS in pigeon pea remains unclear and undetermined. In this study transcriptome analysis for exploring differentially expressed genes (DEGs) between cytoplasmic male-sterile line (AKCMS11) and its fertility restorer line (AKPR303) was performed using Illumina paired-end sequencing.ResultsA total of 3167 DEGs were identified, of which 1432 were up-regulated and 1390 were down-regulated in AKCMS11 in comparison to AKPR303. By querying, all the 3167 DEGs against TAIR database, 34 pigeon pea homologous genes were identified, few involved in pollen development (EMS1, MS1, ARF17) and encoding MYB and bHLH transcription factors with lower expression in the sterile buds, implying their possible role in pollen sterility. Many of these DEGs implicated in carbon metabolism, tricarboxylic acid cycle (TCA), oxidative phosphorylation and elimination of reactive oxygen species (ROS) showed reduced expression in the AKCMS11 (sterile) buds.ConclusionThe comparative transcriptome findings suggest the potential role of these DEGs in pollen development or abortion, pointing towards their involvement in cytoplasmic male-sterility in pigeon pea. The candidate DEGs identified in this investigation will be highly significant for further research, as they could lend a comprehensive basis in unravelling the molecular mechanism governing CMS in pigeon pea.

Highlights

Pigeon pea (Cajanus cajan L.) is the sixth major legume crop widely cultivated in the Indian sub-continent, Africa, and South-east Asia
We found 10 differentially expressed genes (DEGs) involved in regulation of pollen development, among which 1 DEG encoding EXCESS MICROSPOROCYTES 1 (EMS1), 1 DEG encoding PHD-finger transcription factor MALE
We examined a total of 15 DEGs involved in the elimination of reactive oxygen species (ROS), including 2 DEGs encoding peroxidase-like, 1 DEG encoding superoxide dismutase and 2 DEG encoding peroxiredoxin-2B-like, along with 1 DEG encoding glutathione S-transferase and 1 DEG encoding for glutathione peroxidase

Summary

Introduction

Pigeon pea (Cajanus cajan L.) is the sixth major legume crop widely cultivated in the Indian sub-continent, Africa, and South-east Asia. Cytoplasmic male-sterility (CMS) is the incompetence of flowering plants to produce viable pollens during anther development. Cytoplasmic male-sterility (CMS) is a maternally inherited trait in plants where they are unable to produce functional pollens [1]. Cytoplasmic male-sterility phenotype is known to be restored by nuclear genes termed as the restorer of fertility (Rf) and result in the Saxena et al BMC Plant Biology (2020) 20:74 along with functional dominant Rf gene(s). The F1 hybrids produced possess dominant Rf gene to restores the malefertility and the blend of nuclear genes from the sterile and fertile lines results in hybrid vigor [2]. In pigeon pea the gene associated with cytoplasmic male-sterility has not been much explored

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Conclusion