Qin, J., Scheuring, C. F., Wei, G., Zhi, H., Zhang, M., Huang, J. J., Zhou, X., Galbraith, D. W., & Zhang, H. (2013). Identification and characterization of a repertoire of genes differentially expressed in developing top ear shoots between a superior hybrid and its parental inbreds in Zea mays L.. Molecular Genetics and Genomics, 288(12), 691-705.
PMID: 24146224;Abstract:
Heterosis has been widely used in crop breeding and production; however, little is known about the genes controlling trait heterosis. The shortage of genes known to function in heterosis significantly limits our understanding of the molecular basis underlying heterosis. Here, we report 748 genes differentially expressed (DG) in the developing top ear shoots between a maize heterotic F1 hybrid (Mo17 × B73) and its parental inbreds identified using maize microarrays containing 28,608 unigene features. Of the 748 DG, over 600 were new for the inbred and hybrid combination. The DG were enriched for 35 of the total 213 maize gene ontology (GO) terms, including those describing photosynthesis, respiration, DNA replication, metabolism, and hormone biosynthesis. From the DG, we identified six genes involved in glycolysis, three genes in the citrate cycle, and four genes in the C4-dicarboxylic acid cycle. We mapped 533 of the 748 DG to the maize B73 genome, 298 (55.9 %) of which mapped to the QTL intervals of 11 maize ear traits. Moreover, we compared the repertoire of the DG with that of 14-day seedlings of the same inbred and hybrid combination. Only approximately 5 % of the DG was shared between the two organs and developmental stages. Furthermore, we mapped 417 (55.7 %) of the 748 maize DG to the QTL intervals of 26 rice yield-related traits. Therefore, this study provides a repertoire of genes useful for identification of genes involved in maize ear trait heterosis and information for a better understanding of the molecular basis underlying heterosis in maize. © 2013 Springer-Verlag Berlin Heidelberg.
Liu, Y., Zhu, X., Zhang, S., Bernardo, M., Edwards, J., Galbraith, D., Leach, J., Zhang, G., Liu, B., & Leung, H. (2011). Dissecting quantitative resistance against blast using heterogeneous inbred families in rice. Theoretical and Applied Genetics, 122, 341-353.
Song, C., & Galbraith, D. W. (2006). AtSAP18, an orthologue of human SAP18, is involved in the regulation of salt stress and mediates transcriptional repression in Arabidopsis. Plant Molecular Biology, 60(2), 241-257.
PMID: 16429262;Abstract:
In yeast and mammalian systems, it is well established that transcriptional down-regulation by DNA-binding repressors involves core histone deacetylation, mediated by their interaction within a complex containing histone deacetylase (e.g. HDA1), as well as various other proteins (e.g. SIN3, SAP18, SAP30, and RbAp46). Here we identify that a Arabidopsis thaliana gene related in sequence to SAP18, designated AtSAP18, functions in transcription regulation in plants subjected to salt stress. The AtSAP18 loss- of-function mutant is more sensitive to NaCl, and is impaired in chlorophyll synthesis as compared to the wild-type. Using GST pull-down, two-hybrid, and transient transcription assays, we have characterized SAP18 and HDA1 orthologues and provide evidence that SAP18 and HDA1 function as transcriptional repressors. We further demonstrate that they associate with Ethylene-Responsive Element binding Factors (ERFs) to create a hormone-sensitive multimeric repressor complex under conditions of environmental stress. Our results indicate that AtSAP18 functions to link the HDA complex to transcriptional repressors that are bound to chromatin in a sequence-specific manner, thereby providing the specificity of signal transduction accompanying transcriptional repression under stress conditions. © Springer 2006.
Mathiason, K., Dong, H. e., Grimplet, J., Venkateswari, J., Galbraith, D. W., Etti, O. r., & Fennell, A. (2009). Transcript profiling in Vitis riparia during chilling requirement fulfillment reveals coordination of gene expression patterns with optimized bud break. Functional and Integrative Genomics, 9(1), 81-96.
PMID: 18633655;Abstract:
Endodormant grapevine buds require a period of chilling before they break and begin to grow. Custom Vitis bud cDNA microarrays (9,216 features) were used to examine gene expression patterns in overwintering Vitis riparia buds during 2,000 h of 4°C chilling. Three-node cuttings collected concurrently with buds were monitored to determine dormancy status. Chilling requirement was fulfilled after 1,500 h of chilling; however, 2,000 h of chilling significantly increased the rate of bud break. Microarray analysis identified 1,469 significantly differentially expressed (p value 0.05) array features when 1,000, 1,500, and 2,000 h of chilling were compared to 500 h of chilling. Functional classification revealed that the majority of genes were involved in metabolism, cell defense/stress response, and genetic information processing. The number of significantly differentially expressed genes increased with chilling hour accumulation. The expression of a group of 130 genes constantly decreased during the chilling period. Up-regulated genes were not detected until the later stages of chilling accumulation. Hierarchical clustering of non-redundant expressed sequence tags revealed inhibition of genes involved in carbohydrate and energy metabolism and activation of genes involved in signaling and cell growth. Clusters with expression patterns associated with increased chilling and bud break were identified, indicating several candidate genes that may serve as indicators of bud chilling requirement fulfillment. © Springer-Verlag 2008.
Boyce, J. M., Knight, H., Deyholos, M., Openshaw, M. R., Galbraith, D. W., Warren, G., & Knight, M. R. (2003). The sfr6 mutant of Arabidopsis is defective in transcriptional activation via CBF/DREB1 and DREB2 and shows sensitivity to osmotic stress. Plant Journal, 34(4), 395-406.
PMID: 12753580;Abstract:
The sfr6 mutant of Arabidopsis displays a deficit in freezing tolerance after cold acclimation. We previously observed that the transcripts of three cold-, ABA- and drought-inducible genes, each having a C-repeat motif or the drought-responsive element (CRT/DRE) in its promoter, failed to normally accumulate in this mutant. We now report that the effects of sfr6 upon transcript levels are reflected in the levels of the encoded proteins, confirming that the cold-inducible protein expression is affected by the sfr6 mutation. Using microarray analysis, we found not only that this effect may be general to cold-inducible genes with CRT/DRE promoter elements, but also that it extends to some other genes whose promoters lack a CRT/DRE element. The role of the CRT/DRE has been empirically tested by use of a synthetic promoter, confirming that the CRT/DRE is sufficient to confer the sfr6 effect upon expression. Tolerance of osmotic stress was also found to be reduced in sfr6, consistent with a role in osmotic stress tolerance for the cold-, ABA-and drought-inducible genes whose expression is affected by the sfr6 mutation.
