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International Journal of Genomics
Volume 2017, Article ID 2568706, 14 pages
https://doi.org/10.1155/2017/2568706
Research Article

Genomewide Expression and Functional Interactions of Genes under Drought Stress in Maize

1Division of Genetics, Indian Agricultural Research Institute, New Delhi 110012, India
2Centre for Agricultural Bioinformatics, Indian Agricultural Statistics Research Institute, Pusa, Library Avenue, New Delhi 110 012, India
3National Research Centre on Plant Biotechnology, Pusa Campus, New Delhi 110012, India
4Borlaug Institute for South Asia (BISA), New Delhi 110012, India

Correspondence should be addressed to Nepolean Thirunavukkarasu; moc.liamg@naelopent

Received 8 September 2016; Revised 16 December 2016; Accepted 12 January 2017; Published 23 February 2017

Academic Editor: Mohamed Salem

Copyright © 2017 Nepolean Thirunavukkarasu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

A genomewide transcriptome assay of two subtropical genotypes of maize was used to observe the expression of genes at seedling stage of drought stress. The number of genes expressed differentially was greater in HKI1532 (a drought tolerant genotype) than in PC3 (a drought sensitive genotype), indicating primary differences at the transcriptional level in stress tolerance. The global coexpression networks of the two genotypes differed significantly with respect to the number of modules and the coexpression pattern within the modules. A total of 174 drought-responsive genes were selected from HKI1532, and their coexpression network revealed key correlations between different adaptive pathways, each cluster of the network representing a specific biological function. Transcription factors related to ABA-dependent stomatal closure, signalling, and phosphoprotein cascades work in concert to compensate for reduced photosynthesis. Under stress, water balance was maintained by coexpression of the genes involved in osmotic adjustments and transporter proteins. Metabolism was maintained by the coexpression of genes involved in cell wall modification and protein and lipid metabolism. The interaction of genes involved in crucial biological functions during stress was identified and the results will be useful in targeting important gene interactions to understand drought tolerance in greater detail.