Email updates

Keep up to date with the latest news and content from BMC Genomics and BioMed Central.

Open Access Research article

Functional genomics of fuzzless-lintless mutant of Gossypium hirsutum L. cv. MCU5 reveal key genes and pathways involved in cotton fibre initiation and elongation

Kethireddy Venkata Padmalatha1, Deepak P Patil2, Krishan Kumar2, Gurusamy Dhandapani1, Mogilicherla Kanakachari1, Mullapudi LV Phanindra1, Saravanan Kumar2, T C Mohan3, Neha Jain1, Arkalgud H Prakash4, Hiremath Vamadevaiah3, Ishwarappa S Katageri3, Sadhu Leelavathi2, Malireddy K Reddy2, Polumetla Ananda Kumar1 and Vanga Siva Reddy2*

Author Affiliations

1 National Research Centre on Plant Biotechnology, Pusa Campus, New Delhi, 110 012, India

2 Plant Transformation Group, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India

3 Agricultural Research Station, Dharwad Farm, University of Agricultural Sciences, Dharwad, India

4 Central Institute for Cotton Research, Regional Station, Coimbatore, Tamil Nadu, India

For all author emails, please log on.

BMC Genomics 2012, 13:624  doi:10.1186/1471-2164-13-624

Published: 14 November 2012

Abstract

Background

Fuzzless-lintless cotton mutants are considered to be the ideal material to understand the molecular mechanisms involved in fibre cell development. Although there are few reports on transcriptome and proteome analyses in cotton at fibre initiation and elongation stages, there is no comprehensive comparative transcriptome analysis of fibre-bearing and fuzzless-lintless cotton ovules covering fibre initiation to secondary cell wall (SCW) synthesis stages. In the present study, a comparative transcriptome analysis was carried out using G. hirsutum L. cv. MCU5 wild-type (WT) and it’s near isogenic fuzzless-lintless (fl) mutant at fibre initiation (0 dpa/days post anthesis), elongation (5, 10 and 15 dpa) and SCW synthesis (20 dpa) stages.

Results

Scanning electron microscopy study revealed the delay in the initiation of fibre cells and lack of any further development after 2 dpa in the fl mutant. Transcriptome analysis showed major down regulation of transcripts (90%) at fibre initiation and early elongation (5 dpa) stages in the fl mutant. Majority of the down regulated transcripts at fibre initiation stage in the fl mutant represent calcium and phytohormone mediated signal transduction pathways, biosynthesis of auxin and ethylene and stress responsive transcription factors (TFs). Further, transcripts involved in carbohydrate and lipid metabolisms, mitochondrial electron transport system (mETS) and cell wall loosening and elongation were highly down-regulated at fibre elongation stage (5–15 dpa) in the fl mutant. In addition, cellulose synthases and sucrose synthase C were down-regulated at SCW biosynthesis stage (15–20 dpa). Interestingly, some of the transcripts (~50%) involved in phytohormone signalling and stress responsive transcription factors that were up-regulated at fibre initiation stage in the WT were found to be up-regulated at much later stage (15 dpa) in fl mutant.

Conclusions

Comparative transcriptome analysis of WT and its near isogenic fl mutant revealed key genes and pathways involved at various stages of fibre development. Our data implicated the significant role of mitochondria mediated energy metabolism during fibre elongation process. The delayed expression of genes involved in phytohormone signalling and stress responsive TFs in the fl mutant suggests the need for a coordinated expression of regulatory mechanisms in fibre cell initiation and differentiation.