Project description:Recently, intensive global climate change has become a major factor impacting plant survival during the winter. Freezing cold temperatures during the winter and abnormal temperature fluctuations during the winter and early spring are the most harmful ambient factors threatening tea plant winter survival and currently cause marked economic losses in tea production. In this study, by simulating natural climate change, we established cold acclimation (CA) and rapid cold stress (after CA) conditions to comprehensively investigate the transcriptome changes involved in CA and rapid cold stress. Electrolyte leakage (EL) rate and expression profile clustering analyses confirmed that the experimental design was valid. Comparative transcription analysis identified many differentially expressed genes (DEGs) involved in both processes. Time course and pathway enrichment analyses further revealed the physiological changes that occur during the initial period of CA and the cell wall changes that occur throughout the entire CA process; these changes play crucial roles in increasing freezing tolerance during this process. Compared with CA, different cold response mechanisms were rapidly activated under cold stress; however, the subsequent accumulation of reactive oxygen species, which affect multiple aspects, caused by freezing cold could be the harshest factor impairing tea leaves. Moreover, we investigated 60 DEGs shared by both processes and highlighted the importance of KCSs, HXXXD-type acyl-transferase family proteins, NAC080, SWEETs and ENOs in the responses to various cold conditions. These results greatly improve our knowledge of cold response mechanisms in tea plants and provide meaningful information for functional studies investigating cold tolerance-related genes.
Project description:Cold is a major naturally occurring stress that usually causes complex symptoms and severe yield loss in plants. R-loops can function in a series of biological processes, including normal development and stress responses, in plants. However, how R-loops function in cold responses is still largely unknown in plants, especially in cold sensitive rice. Herein, we conducted DRIP-seq in combination with other newly generated omics data (RNA-seq, DNase-seq, ChIP-seq and MNase-seq) in rice with or without cold treatment. We found that cold treatment caused R-loop dynamics across the genome, indicating that R-loops are cold sensitive non-B DNA structures. Moreover, cold biased R-loops had high GC content and novel motifs the binding of distinct TFs as compared to CK biased R-loops, indicative of occurrence of differential biological implications of R-loop dynamics in response to cold stress. More importantly, we for the first time to provide evidence showing that, in addition to the direct involvement of R-loops in the regulation of cold-responsive gene transcription, R-loops can indirectly modulate transcription of subsets of cold-responsive genes through R-loop overlapping TF-centered or cis-regulatory element related regulatory networks and lncRNAs in rice. Thus, our study for the first time provides evidence showing functions of R-loop dynamics in rice cold responses. It also provides some potential R-loop loci for genetic and epigenetic manipulation towards breeding of enhanced cold tolerance rice varieties.
Project description:Despite their early evolutionary divergence, reef-building corals exhibit complex circadian responses to diurnal, lunar and annual changes in the conditions around them. Understanding circadian regulation in reef-building corals is, however, complicated by the presence of photosynthetic endosymbionts that have a profound physiochemical influence on the intracellular environment. How corals tune their animal-based clock machinery to respond to external cues while at the same time responding to internal physiological changes imposed by the symbiont is not clear. We explore this issue using microarray analysis to dissect genes governed directly by the circadian machinery from those responding indirectly as a consequence of changing internal oxygen tensions.
Project description:Epigenetic markers, such as DNA methylation, in sperm plays crucial roles in spermatogenesis and fertilization, and a portion of methylation escape the early embryonic genome-wide DNA demethylation and affect later growth and development of offspring. DNA methylation is influenced by various exogenous factors such as nutrition, temperature, toxicants, and stress. The effects of this cold exposure on the methylation dynamics of bovine sperm remain unexamined. Methylation profiles of sperm, collected from bulls during summer and winter seasons were analyzed by Whole Genome Bisulfite Sequencing (WGBS). Cold exposure during winter does not have a significant effect on the global methylation level, it altered the methylation levels at certain genomic loci and genes that may impact the maintenance of methylation status of imprinted genes and other loci, which may impact the development and growth of offspring.
Project description:Winter turnip rape (Brassica rapa L.) is a valuable ecologically beneficial oil crop that is produced mainly for its ability of conserving soil and water in winter and spring and its high quality edible oil in northwestern China. However, coldness and extremely low temperature negatively affects the growth and development of winter turnip rape, resulting in failure to overwinter and production in northwestern China. ‘Longyou 7’(Brassica rapa L.) and ‘Tianyou 4’ (Brassica rapa L.) are closely related plant species, but their cold tolerances are different. ‘Longyou 7’ is a cold-tolerant cultivar, ‘Tianyou 4’is a cold-sensitive cultivar. In this study, we used iTRAQ-based proteomics to compare quantitative changes in the proteome of two winter turnip rape leaves and roots in response to cold stress to elucidate the possible molecular mechanism underlying the ability of ‘Longyou 7’ to adapt to cold stress.
Project description:Winter turnip rape (Brassica rapa L.) is a valuable ecologically beneficial oil crop that is produced mainly for its ability of conserving soil and water in winter and spring and its high quality edible oil in northwestern China. However, coldness and extremely low temperature negatively affects the growth and development of winter turnip rape, resulting in failure to overwinter and production in northwestern China. ‘Longyou 7’(Brassica rapa L.) and ‘Tianyou 4’ (Brassica rapa L.) are closely related plant species, but their cold tolerances are different. ‘Longyou 7’ is a cold-tolerant cultivar, ‘Tianyou 4’is a cold-sensitive cultivar. In this study, we used iTRAQ-based proteomics to compare quantitative changes in the proteome of two winter turnip rape leaves and roots in response to cold stress to elucidate the possible molecular mechanism underlying the ability of ‘Longyou 7’ to adapt to cold stress.
Project description:Despite their early evolutionary divergence, reef-building corals exhibit complex circadian responses to diurnal, lunar and annual changes in the conditions around them. Understanding circadian regulation in reef-building corals is, however, complicated by the presence of photosynthetic endosymbionts that have a profound physiochemical influence on the intracellular environment. How corals tune their animal-based clock machinery to respond to external cues while at the same time responding to internal physiological changes imposed by the symbiont is not clear. We explore this issue using microarray analysis to dissect genes governed directly by the circadian machinery from those responding indirectly as a consequence of changing internal oxygen tensions. Three coral colonies were sampled at 4 hr intervals during two consecutive days under an ambient light/dark (LD) cycle and under constant darkness (DD). In total 72 arrays were hybridized, as each array represented a sample from a treatment and a time point (n=3).
Project description:Different wheat cultivars may be classified as either winter or spring varieties depending on whether they require exposure to an extended period of cold in order to become competent to flower. Using a growth regime that mimics the conditions that occur during a typical winter in Britain, we wished to survey the genes that are involved in phase transition as well as those involved in cold-acclimation. Keywords: Time course
Project description:Gene expression changes in a winter cultivar of barley in response to short and long term cold treatments ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Ben Trevaskis. The equivalent experiment is BB94 at PLEXdb.]