|Brown, Anne - Purdue University|
Submitted to: Plant Cell and Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/2/2017
Publication Date: 7/19/2017
Citation: Brown, A., Hudson, K.A. 2017. Transcriptional profiling of mechanically and genetically sink-limited soybeans. Plant Cell and Environment. doi:10.1111/pce.13030.
Interpretive Summary: Soybean is an annual crop plant - once seeds are produced and reach maturity the leaves and stems senesce and die. The life of the plant can be extended by the removal of soybean flowers or pods as they form, or in the case of plants that do not produce seeds (sterile plants). To understand the genetic and molecular controls of plant senescence in soybean, we used RNA sequencing technology to profile gene expression in leaves of soybean that did not produce pods (either by mechanical or genetic methods). The study of the expression and function of these genes has the potential to identify genes that can improve soybean yield and better control the period of active photosynthesis, and resource allocation in soybean plants.
Technical Abstract: The absence of a reproductive sink causes physiological and morphological changes in soybean plants. These include increased accumulation of nitrogen and starch in the leaves and delayed leaf senescence. To identify transcriptional changes that occur in leaves of these sink-limited plants, we used RNAseq to compare gene expression levels in trifoliate leaves from depodded and ms6 male sterile soybean plants and control plants. In both sink-limited tissues, we observed a deferral of the expression of senescence-associated genes and a continued expression of genes associated with leaf maturity. GO-terms associated with growth and development and storage proteins were over-represented in genes that were differentially expressed in sink-limited tissues. We also identified bHLH, ARF, and SBP transcription factors expressed in sink-limited tissues, while the senescing control leaves expressed WRKY and NAC transcription factors. We identified genes that were not expressed during normal leaf development but that were highly expressed in sink-limited plants, including the SGR3b “non-yellowing” gene. These differences highlighted several metabolic pathways that were involved in distinct modes of resource partitioning of leaves with the “stay green” phenotype.