Characterization of a new rice OsMADS1 null mutant generated by homologous recombination-mediated gene targeting

Kannan, P and Chongloi, GL and Majhi, BB and Basu, D and Veluthambi, K and Vijayraghavan, U (2021) Characterization of a new rice OsMADS1 null mutant generated by homologous recombination-mediated gene targeting. In: Planta, 253 (2).

	PDF Planta_253_2.pdf - Published Version Restricted to Registered users only Download (1MB) | Request a copy
	Microsoft Word 425_2020_3547_MOESM9_ESM.docx - Published Supplemental Material Restricted to Registered users only Download (18kB) | Request a copy

Abstract

Main conclusion: A new, stable, null mutant of OsMADS1 generated by homologous recombination-based gene targeting in an indica rice confirms its regulatory role for floral meristem identity, its determinate development and floral organ differentiation. Abstract: OsMADS1, an E-class MADS-box gene, is an important regulator of rice flower development. Studies of several partial loss-of-function and knockdown mutants show varied floret organ defects and degrees of meristem indeterminacy. The developmental consequences of a true null mutant on floret meristem identity, its determinate development and differentiation of grass-specific organs such as the lemma and palea remain unclear. In this study, we generated an OsMADS1 null mutant by homologous recombination-mediated gene targeting by inserting a selectable marker gene (hpt) in OsMADS1 and replacing parts of its cis-regulatory and coding sequences. A binary vector was constructed with diphtheria toxin A chain gene (DT-A) as a negative marker to eliminate random integrations and the hpt marker for positive selection of homologous recombination. Precise disruption of the endogenous OsMADS1 locus in the rice genome was confirmed by Southern hybridization. The homozygous osmads1ko null mutant displayed severe defects in all floral organs including the lemma and palea. We also noticed striking instances of floral reversion to inflorescence and vegetative states which has not been reported for other mutant alleles of OsMADS1 and further reinforces the role of OsMADS1 in controlling floral meristem determinacy. Our data suggest, OsMADS1 commits and maintains determinate floret development by regulating floral meristem termination, carpel and ovule differentiation genes (OsMADS58, OsMADS13) while its modulation of genes such as OsMADS15, OsIG1 and OsMADS32 could be relevant in the differentiation and development of palea. Further, our study provides an important perspective on developmental stage-dependent modulation of some OsMADS1 target genes. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.

Item Type:	Journal Article
Publication:	Planta
Publisher:	Springer Science and Business Media Deutschland GmbH
Additional Information:	Copyright to this article belongs to Springer Science and Business Media Deutschland GmbH
Department/Centre:	Division of Biological Sciences > Microbiology & Cell Biology
Date Deposited:	10 Feb 2021 11:46
Last Modified:	10 Feb 2021 11:46
URI:	http://eprints.iisc.ac.in/id/eprint/67860

Actions (login required)

View Item