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Research article2010Peer reviewedOpen access

Significance of Light, Sugar, and Amino Acid Supply for Diurnal Gene Regulation in Developing Barley Caryopses

Mangelsen, Elke; Wanke, Dierk; Kilian, Joachim; Sundberg, Eva; Harter, Claus; Jansson, Christer

Abstract

The caryopses of barley (Hordeum vulgare), as of all cereals, are complex sink organs optimized for starch accumulation and embryo development. While their early to late development has been studied in great detail, processes underlying the caryopses' diurnal adaptation to changes in light, temperature, and the fluctuations in phloem-supplied carbon and nitrogen have remained unknown. In an attempt to identify diurnally affected processes in developing caryopses at the early maturation phase, we monitored global changes of both gene expression and metabolite levels. We applied the 22 K Barley1 GeneChip microarray and identified 2,091 differentially expressed (DE) genes that were assigned to six major diurnal expression clusters. Principal component analysis and other global analyses demonstrated that the variability within the data set relates to genes involved in circadian regulation, storage compound accumulation, embryo development, response to abiotic stress, and photosynthesis. The correlation of amino acid and sugar profiles with expression trajectories led to the identification of several hundred potentially metabolite-regulated DE genes. A comparative analysis of our data set and publicly available microarray data disclosed suborgan-specific expression of almost all diurnal DE genes, with more than 350 genes specifically expressed in the pericarp, endosperm, or embryo tissues. Our data reveal a tight linkage between day/night cycles, changes in light, and the supply of carbon and nitrogen. We present a model that suggests several phases of diurnal gene expression in developing barley caryopses, summarized as starvation and priming, energy collection and carbon fixation, light protection and chaperone activity, storage and growth, and embryo development.

Published in

Plant Physiology
2010, Volume: 153, number: 1, pages: 14-33
Publisher: AMER SOC PLANT BIOLOGISTS

      SLU Authors

      • UKÄ Subject classification

      Renewable Bioenergy Research
      Agricultural Science

      Publication identifier

      DOI: https://doi.org/10.1104/pp.110.154856

      Permanent link to this page (URI)

      https://res.slu.se/id/publ/60862