TMT-based comparative proteomics reveals the role of acyl-CoA oxidase 4 in enhancing the drought stress tolerance in common buckwheat (Fagopyrum esculentum).

Drought stress has been the main abiotic factor affecting the growth, development and production of common buckwheat (Fagopyrum esculentum). To explore the response mechanisms of regulating buckwheat drought stress on the post-transcriptional and translational levels, a comparative proteomic analysis was applied to monitor the short-term proteomic variations under the drought stress in the seedling stage. From which 593 differentially abundant proteins (DAPs) were identified using the TMT-based proteomics analysis. A number of DAPs were found to be intimately correlated with the styrene degradation, phenylpropanoid biosynthesis and stimulus response, within which. The acyl-CoA oxidase 4 (ACX4), a key regulator in plant abiotic stress response, was selected for further elucidation. Overexpression of the FeACX4 not only conferred drought and salt tolerance in the Arabidopsis, but also significantly increased the root length and fresh weight in the overexpression lines plant relative to the wild type (WT) plant, accompanied by the elevated activities of catalase (CAT) and lowered malonaldehyde (MDA) and H2O2 contents, therefore allowing plants to better adapt to adverse environments. Our results provided information in the exploring of the molecular regulation mechanism responding to drought tolerance in common buckwheat.

Transcriptome Analysis Reveals the Accumulation Mechanism of Anthocyanins in Buckwheat (Fagopyrum esculentum Moench) Cotyledons and Flowers.

Buckwheat (Fagopyrum esculentum) is a valuable crop which can produce multiple human beneficial secondary metabolites, for example, the anthocyanins in sprouts and flowers. However, as the predominant group of visible polyphenols in pigmentation, little is known about the molecular mechanisms underlying the anthocyanin biosynthesis within buckwheat. In this study, a comparative transcriptome analysis of green and red common buckwheat cultivars was carried out through RNA sequencing. Overall, 3727 and 5323 differently expressed genes (DEGs) were identified in flowers and cotyledons, respectively. Through GO and KEGG analysis, we revealed that DEGs in flowers and cotyledons are predominately involved in biosynthesis of anthocyanin. A total of 42 unigenes encoding 11 structural enzymes of the anthocyanin biosynthesis were identified as DEGs. We also identified some transcription factor families involved in the regulation of anthocyanin biosynthesis. Real-time qPCR validation of candidate genes was performed in flowers and cotyledons, and the results suggested that the high expression level of structural genes involved in anthocyanin biosynthetic pathway promotes anthocyanin accumulation. Our results provide the insight understanding for coloration of red common buckwheat.

Cytological and Proteomic Analysis of Wheat Pollen Abortion Induced by Chemical Hybridization Agent.

In plants, pollen grain transfers the haploid male genetic material from anther to stigma, both between flowers (cross-pollination) and within the same flower (self-pollination). In order to better understand chemical hybridizing agent (CHA) SQ-1-induced pollen abortion in wheat, comparative cytological and proteomic analyses were conducted. Results indicated that pollen grains underwent serious structural injury, including cell division abnormality, nutritional deficiencies, pollen wall defect and pollen grain malformations in the CHA-SQ-1-treated plants, resulting in pollen abortion and male sterility. A total of 61 proteins showed statistically significant differences in abundance, among which 18 proteins were highly abundant and 43 proteins were less abundant in CHA-SQ-1 treated plants. 60 proteins were successfully identified using MALDI-TOF/TOF mass spectrometry. These proteins were found to be involved in pollen maturation and showed a change in the abundance of a battery of proteins involved in multiple biological processes, including pollen development, carbohydrate and energy metabolism, stress response, protein metabolism. Interactions between these proteins were predicted using bioinformatics analysis. Gene ontology and pathway analyses revealed that the majority of the identified proteins were involved in carbohydrate and energy metabolism. Accordingly, a protein-protein interaction network involving in pollen abortion was proposed. These results provide information for the molecular events underlying CHA-SQ-1-induced pollen abortion and may serve as an additional guide for practical hybrid breeding.