Rapid analysis of seed size in Arabidopsis for mutant and QTL discovery

Department of Biochemistry, University of Otago, PO Box 56, Dunedin 9054, New Zealand. .
Plant Methods (Impact Factor: 2.59). 02/2011; 7(1):3. DOI: 10.1186/1746-4811-7-3
Source: PubMed

ABSTRACT Arabidopsis thaliana is a useful model organism for deciphering the genetic determinants of seed size; however the small size of its seeds makes measurements difficult. Bulk seed weights are often used as an indicator of average seed size, but details of individual seed is obscured. Analysis of seed images is possible but issues arise from variations in seed pigmentation and shadowing making analysis laborious. We therefore investigated the use of a consumer level scanner to facilitate seed size measurements in conjunction with open source image-processing software.
By using the transmitted light from the slide scanning function of a flatbed scanner and particle analysis of the resulting images, we have developed a method for the rapid and high throughput analysis of seed size and seed size distribution. The technical variation due to the approach was negligible enabling us to identify aspects of maternal plant growth that contribute to biological variation in seed size. By controlling for these factors, differences in seed size caused by altered parental genome dosage and mutation were easily detected. The method has high reproducibility and sensitivity, such that a mutant with a 10% reduction in seed size was identified in a screen of endosperm-expressed genes. Our study also generated average seed size data for 91 Arabidopsis accessions and identified a number of quantitative trait loci from two recombinant inbred line populations, generated from Cape Verde Islands and Burren accessions crossed with Columbia.
This study describes a sensitive, high-throughput approach for measuring seed size and seed size distribution. The method provides a low cost and robust solution that can be easily implemented into the workflow of studies relating to various aspects of seed development.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Offspring number and size are key traits determining an individual's fitness and a crop's yield. Yet, extensive natural variation within species is observed for these traits. Such variation is typically explained by trade-offs between fecundity and quality, for which an optimal solution is environmentally dependent. Understanding the genetic basis of seed size and number, as well as any possible genetic constraints preventing the maximization of both, is crucial from both an evolutionary and applied perspective. We investigated the genetic basis of natural variation in seed size and number using a set of Arabidopsis thaliana Multiparent Advanced Generation Inter-Cross (MAGIC) lines. We also tested whether life-history affects seed size, number, and their trade-off. We found that both seed size and seed number are affected by a large number of mostly non-overlapping QTL; suggesting that seed size and seed number can evolve independently. The allele that increases seed size at most identified QTL is from the same natural accession, indicating past occurrence of directional selection for seed size. Although a significant trade-off between seed size and number is observed, its expression depends on life-history characteristics, and generally explains little variance. We conclude that the trade-off between seed size and number might have a minor role in explaining the maintenance of variation in seed size and number, and that seed size could be a valid target for selection.
    Genetics 10/2014; DOI:10.1534/genetics.114.170746 · 4.87 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Abiotic and biotic stresses alter genome stability and physiology of plants. Under some stressful situations, a state of stress tolerance can be passed on to the offspring rendering them more suitable to stressful events than their parents. In plants, the exploration of transgenerational response has remained exclusive to model species, such as Arabidopsis thaliana. Here, we expand transgenerational research to include Brassica rapa, a close relative to economically important plant canola (Brassica napus), as it is exposed to the biotic stress of a double-stranded DNA virus Cauliflower mosaic virus (CaMV). Parent plants exposed to a low dose of 50ng purified CaMV virions just prior to the bolting stage produced significantly larger seeds than mock inoculated and healthy treatments. The progeny from these large seeds displayed resistance to the pathogen stress applied in the parental generation. Differences in defense pathways involving fatty acids, and primary and secondary metabolites were detected by de novo transcriptome sequencing of CaMV challenged progeny exhibiting different levels of resistance. Our study highlights biological and cellular processes that may be linked to the growth and yield of economically important B. rapa, in a transgenerational manner. Although much remains unknown as to the mechanisms behind transgenerational inheritance, our work shows a disease resistance response that persists for several weeks and is associated with an increase in seed size. Evidence suggests that a number of changes involved in the persistent stress adaption are reflected in the transcriptome. The results from this study demonstrate that treating B. rapa with a dsDNA within a critical time frame and with a specified amount of infectious pathogen produces economically important agricultural plants with superior coping strategies for growing in unfavorable conditions. Copyright © 2014. Published by Elsevier B.V.
    Gene 12/2014; 557(2). DOI:10.1016/j.gene.2014.12.016 · 2.08 Impact Factor
  • Crop Science 01/2014; 54(2):520. DOI:10.2135/cropsci2013.07.0471 · 1.48 Impact Factor

Full-text (3 Sources)

Available from
Jun 1, 2014

Similar Publications