Email updates

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

Open Access Highly Accessed Research article

Tissue culture-induced genetic and epigenetic alterations in rice pure-lines, F1 hybrids and polyploids

Xiaoran Wang1, Rui Wu16, Xiuyun Lin3, Yan Bai1, Congdi Song1, Xiaoming Yu12, Chunming Xu1, Na Zhao4, Yuzhu Dong5* and Bao Liu1*

Author Affiliations

1 Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, China

2 School of Bioengineering, Jilin College of Agricultural Science & Technology, Jilin, 132301, China

3 Jilin Academy of Agricultural Sciences, Changchun, 130033, China

4 Faculty of Agronomy, Jilin Agricultural University, Changchun, 13118, China

5 School of Life Science, Changchun Normal University, Changchun, 130032, China

6 Present address: Carnegie Institution for Science, Department of Plant Biology, Stanford University, Stanford, CA, 94305, USA

For all author emails, please log on.

BMC Plant Biology 2013, 13:77  doi:10.1186/1471-2229-13-77

Published: 5 May 2013

Abstract

Background

Genetic and epigenetic alterations can be invoked by plant tissue culture, which may result in heritable changes in phenotypes, a phenomenon collectively termed somaclonal variation. Although extensive studies have been conducted on the molecular nature and spectrum of tissue culture-induced genomic alterations, the issue of whether and to what extent distinct plant genotypes, e.g., pure-lines, hybrids and polyploids, may respond differentially to the tissue culture condition remains poorly understood.

Results

We investigated tissue culture-induced genetic and epigenetic alterations in a set of rice genotypes including two pure-lines (different subspecies), a pair of reciprocal F1 hybrids parented by the two pure-lines, and a pair of reciprocal tetraploids resulted from the hybrids. Using two molecular markers, amplified fragment length polymorphism (AFLP) and methylation-sensitive amplified polymorphism (MSAP), both genetic and DNA methylation alterations were detected in calli and regenerants from all six genotypes, but genetic alteration is more prominent than epigenetic alteration. While significant genotypic difference was observed in frequencies of both types of alterations, only genetic alteration showed distinctive features among the three types of genomes, with one hybrid (N/9) being exceptionally labile. Surprisingly, difference in genetic alteration frequencies between the pair of reciprocal F1 hybrids is much greater than that between the two pure-line subspecies. Difference also exists in the pair of reciprocal tetraploids, but is to a less extent than that between the hybrids. The steady-state transcript abundance of genes involved in DNA repair and DNA methylation was significantly altered in both calli and regenerants, and some of which were correlated with the genetic and/or epigenetic alterations.

Conclusions

Our results, based on molecular marker analysis of ca. 1,000 genomic loci, document that genetic alteration is the major cause of somaclonal variation in rice, which is concomitant with epigenetic alterations. Perturbed expression by tissue culture of a set of 41 genes encoding for enzymes involved in DNA repair and DNA methylation is associated with both genetic and epigenetic alterations. There exist fundamental differences among distinct genotypes, pure-lines, hybrids and tetraploids, in propensities of generating both genetic and epigenetic alterations under the tissue culture condition. Parent-of-origin has a conspicuous effect on the alteration frequencies.