Project description:Due to the broad climate adaptation of perennial trees, phenological traits (e.g. chilling requirement-CR, bloom date-BD) exhibit complex inheritance patterns. Conceptually, these are adaptive responses to abiotic stress. As production depends on traits like CR, breeders have developed varieties that are phenotypically/genotypically matched to particular geographic/temperature zones. These genotypes are ideal for study of gene networks governing these climate-critical traits. Using genetic approaches, genome-wide association analyses, functional and comparative genomics in fruit and forest trees, we identified a foundational network of genetic activity (phenylpropanoid pathway) linking winter cold stress response to control of the endodormancy-ecodormancy transition (EET) and seed stratification. Our goal is to examine during endodormancy the allelic effects of genes controlling the production of stress related metabolic intermediates that regulate seed stratification, thus linking these two cold temperature responses. Our objective is to use a transcriptome sequencing approach to characterize genotypic effects on the phenylpropanoid gene network transcriptome during endodormancy and the EET. These adaptive genes and gene networks will be targets for knowledge based breeding strategies of fruit and forest trees to sustain and improve these resources to meet the challenges of rapid environmental change
2020-03-23 | GSE138792 | GEO
Project description:Abiotic stress response and adaptive phenology in fruit trees.
Project description:Manipulating the crop load in peach trees determines carbon supply and optimum balance between fruit yield and quality potentials. The impact of carbon supply on peach fruit quality was assessed in three development stages (S2, S3, S4) on fruit of equal maturity from trees that were carbon (C) starved (unthinned) and sufficient (thinned). Previous studies determined that primary metabolites of peach fruit mesocarp are mainly linked with developmental processes, thus, the secondary metabolite profile was assessed using non-targeted liquid chromatography mass-spectrometry (LC-MS). Carbon sufficient (C-sufficient) fruit demonstrated superior quality attributes as compared to C-starved fruit. Early metabolic shifts in the secondary metabolome appear to prime quality at harvest. Enhanced C-availability facilitated the increased and consistent synthesis of flavonoids, like catechin, epicatechin and eriodyctiol, via the phenylpropanoid pathway, providing a link between the metabolome and fruit quality, and serving as signatures of C-sufficiency during peach fruit development.
Project description:To assess the reproducibility of the microarray analysis, we repeated the experiment three times with independently prepared total RNA. Keywords = abiotic stress Keywords: repeat sample
Project description:In this data set, we reported for the first time that huanglongbing disease (HLB) induces major changes in the expression of global genes in flavedo, vascular and juice vesicle tissues of citrus fruit.
Project description:Background: WitchesM-bM-^@M-^Y broom disease of Mexican lime (Citrus aurantifolia L.), which is caused by the phytoplasma M-bM-^@M-^\Candidatus Phytoplasma aurantifoliaM-bM-^@M-^], is a devastating disease that results in significant economic losses. Plants adapt to abiotic stresses by regulating gene expression at the transcriptional and post-transcriptional levels. MicroRNAs (miRNAs) are a recently identified family of molecules that regulate plant responses to environmental stresses through post-transcriptional gene silencing. Methods: Using a high-throughput approach to sequence small RNAs, we compared the expression profiles of miRNAs in healthy Mexican lime trees and in plants infected with M-bM-^@M-^\Ca. Phytoplasma aurantifoliaM-bM-^@M-^]. Results: Our results demonstrated the involvement of different miRNAs in the response of Mexican lime trees to infection by M-bM-^@M-^\Ca. Phytoplasma aurantifoliaM-bM-^@M-^]. We identified miRNA families that are expressed differentially upon infection with phytoplasmas. Most of the miRNAs had variants with small sequence variations (isomiRs), which are expressed differentially in response to pathogen infection. Conclusions: It is likely that the miRNAs that are expressed differentially in healthy and phytoplasma-infected Mexican lime trees are involved in coordinating the regulation of hormonal, nutritional, and stress signalling pathways, and the complex interactions between them. Future research to elucidate the roles of these miRNAs should improve our understanding of the level of diversity of specific plant responses to phytoplasmas. Small mRNA profiles of healthy (H) and Phytoplasma-infected Mexican lime trees were generated by deep sequencing, six replicate, using Illumina Hiseq2000
Project description:Background: Witches’ broom disease of Mexican lime (Citrus aurantifolia L.), which is caused by the phytoplasma “Candidatus Phytoplasma aurantifolia”, is a devastating disease that results in significant economic losses. Plants adapt to abiotic stresses by regulating gene expression at the transcriptional and post-transcriptional levels. MicroRNAs (miRNAs) are a recently identified family of molecules that regulate plant responses to environmental stresses through post-transcriptional gene silencing. Methods: Using a high-throughput approach to sequence small RNAs, we compared the expression profiles of miRNAs in healthy Mexican lime trees and in plants infected with “Ca. Phytoplasma aurantifolia”. Results: Our results demonstrated the involvement of different miRNAs in the response of Mexican lime trees to infection by “Ca. Phytoplasma aurantifolia”. We identified miRNA families that are expressed differentially upon infection with phytoplasmas. Most of the miRNAs had variants with small sequence variations (isomiRs), which are expressed differentially in response to pathogen infection. Conclusions: It is likely that the miRNAs that are expressed differentially in healthy and phytoplasma-infected Mexican lime trees are involved in coordinating the regulation of hormonal, nutritional, and stress signalling pathways, and the complex interactions between them. Future research to elucidate the roles of these miRNAs should improve our understanding of the level of diversity of specific plant responses to phytoplasmas.
Project description:Early stages of fruit growth from initial set through exponential growth are critical determinants of size and yield, however, there has been little detailed analysis of this phase of development. In this study we combined morphological analysis with 454 pyrosequencing to study gene expression changes occurring in young cucumber fruit at five ages from anthesis through the end of exponential growth. The resulting 1.13 million ESTs were assembled into 27,859 contigs with a mean length of 834 base pairs and a mean of 67 reads per contig. Principal component analysis separated the fruit ages into three groups corresponding with cell division/pre-exponential growth (0 and 4 days post pollination (dpp)), peak exponential expansion (8dpp), and late/post-exponential expansion stages of growth (12 and 16 dpp). Transcripts predominantly expressed at 0 and 4 dpp included homologs of histones, cyclins, and plastid and photosynthesis related genes. The group of genes with peak expression at 8dpp included cytoskeleton, cell wall, and lipid metabolism related genes and phloem specific proteins. This group also was dominated by genes with unknown function or without Arabidopsis homologs, suggesting unique factors contributing to the rapid growth phase in cucurbits. A second shift in gene expression was observed at 12-16dpp, which was characterized by abiotic and biotic stress related genes and significant enrichment for stress related- and developmental- transcription factor gene homologs. Collectively, the gene expression information coupled with morphological analyses tells a progressive story of cell division, development of photosynthetic capacity, cell expansion and fruit growth, phloem activity, protection of the fruit surface, and finally transition away from fruit growth toward defense and maturation. mRNA profiling of early fruit development using 454 sequencing.
Project description:Roughing disorder (RD) is a significant quality barrier in citrus fruit, occurring more easily on easy-peeling mandarins. As RD is not yet well understood, this study aimed to examine the changes and synergic molecular processes involved. Peel with RD was induced by severely defruiting Satsuma mandarin trees. Morphology observations, RNA-sequencing and untargeted and targeted metabolic analyses were conducted.