Project description:Heading date1(Hd1) is a critical regulator controlling rice flowering time, which promotes flowering under short-day (SD) conditions and represses flowering under long-day (LD) conditions. In our previous study (Luan et al., 2009), we identified a rice mutant, hd1-3, in which the Hd1 gene was deficient due to several insertions/deletions in the coding region. To search for downstream genes regulated by Hd1, we performed microarray analysis of hd1-3 mutant and the wild-type Zhonghua11 under both SD and LD conditions. According to the microarray results, SDG712 gene was significantly downregulated in the hd1-3 mutant, indicating that SDG712 gene may acts downstream of Hd1, and may functions in rice flowering time regulation.
Project description:A great majority of plants synchronize flowering with day length. In rice, the most important environmental cue that triggers flowering is the photoperiod. Here, we show that the s73 mutant, identified in a gamma irradiated Bahia collection, displays early flowering and photoperiodic insensitivity due to a null mutation in the SE5 gene, which encodes an enzyme implicated in phytochrome chromophore biosynthesis. s73 mutant plants showed a number of alterations in the characteristic diurnal expression patterns of master genes involved in photoperiodic control of flowering, resulting in up-regulation of Hd3a, the most important floral integrator. Ehd1, an additional rice floral activator, was also highly expressed in the s73 mutant, suggesting that SE5 represses Ehd1 in wild-type plants. Silencing of Ehd1 in both Bahia and s73 backgrounds implies that SE5 regulates Ehd1 expression. The data also indicate that SE5 confers photoperiodic sensitivity through regulation of Hd1. These results provide direct evidence that phytochromes inhibit flowering affecting both Hd1 and Ehd1 flowering pathways.
Project description:A great majority of plants synchronize flowering with day length. In rice, the most important environmental cue that triggers flowering is the photoperiod. Here, we show that the s73 mutant, identified in a gamma irradiated Bahia collection, displays early flowering and photoperiodic insensitivity due to a null mutation in the SE5 gene, which encodes an enzyme implicated in phytochrome chromophore biosynthesis. s73 mutant plants showed a number of alterations in the characteristic diurnal expression patterns of master genes involved in photoperiodic control of flowering, resulting in up-regulation of Hd3a, the most important floral integrator. Ehd1, an additional rice floral activator, was also highly expressed in the s73 mutant, suggesting that SE5 represses Ehd1 in wild-type plants. Silencing of Ehd1 in both Bahia and s73 backgrounds implies that SE5 regulates Ehd1 expression. The data also indicate that SE5 confers photoperiodic sensitivity through regulation of Hd1. These results provide direct evidence that phytochromes inhibit flowering affecting both Hd1 and Ehd1 flowering pathways. Four biological replicates from each genotype (s73 mutant and Bahia wt) were labelled with Cy3 and Cy5 alternatively (2+2) following a dye-swap design. In total, 4 microarrays were hybridized. The supplementary file 'GSE16796_stat_analysis.txt' contains the final statistical analysis of study GSE16796.
Project description:To reveal the underlying molecular mechanism of Gif1 action in the control of grain filling and yield improvement, we performed transcriptional profiling of wild type Zhonghua11 and mutant gif1 plants in early filling stage on a global scale using the Affymetrix GeneChip Rice Genome Array Experiment Overall Design: Rice caryopsis were harvested in 7 days after flowering and three biological repeats were performed on Zhonghua11 (wild-type) and gif1 (mutant), respectively.
Project description:Sustainable agriculture requires locally adapted varieties that produce nutritious food with limited agricultural inputs. Genome engineering represents a viable approach to develop cultivars that fulfill these criteria. For example, the red Hassawi rice, a native landrace of Saudi Arabia, tolerates local drought and high-salinity conditions and produces grain with diverse health-promoting phytochemicals. However, Hassawi has a long growth cycle, high cultivation costs, low productivity, and susceptibility to lodging. Here, to improve these undesirable traits via genome editing, we established efficient regeneration and Agrobacterium-mediated transformation protocols for Hassawi. In addition, we generated the first high-quality reference genome and targeted the key flowering repressor gene, Hd4, thus shortening the plant's lifecycle and height. Using CRISPR/Cas9 multiplexing, we simultaneously disrupted negative regulators of flowering time (Hd2, Hd4, and Hd5), grain size (GS3), grain number (GN1a), and plant height (Sd1). The resulting homozygous mutant lines flowered extremely early (∼56 days) and had shorter stems (approximately 107 cm), longer grains (by 5.1%), and more grains per plant (by 50.2%), thereby enhancing overall productivity. Furthermore, the awns of grains were 86.4% shorter compared to unedited plants. Moreover, the modified rice grain displayed improved nutritional attributes. As a result, the modified Hassawi rice combines several desirable traits that can incentivize large-scale cultivation and reduce malnutrition.
Project description:This study aim to understand how the long and short day flowering pathways are integrated and the mechanism of photoperiod perception in rice. Trascriptome at different time points under LD and SD conditions reveal that photoperiodism in rice is controlled by the evening complex. Mutants in LUX ARRYTHMO (LUX) and EARLY FLOWERING3 (ELF3) orthologs abolish flowering. We show that light causes a rapid and sustained degradation of ELF3-1, and this response is dependent on phyB. ChIP-seq of ELF3 and LUX reveal that EC controls both LD and SD flowering pathways by directly binding and suppressing the expression of key floral repressors, including PRR7 orthologs and Ghd7.
Project description:A heat and drought tolerant rice cultivar (N22) was grown in the field under control and drought conditions during the dry season in 2013. Drought was applied during early grain filling and resulted in simultaneous heat stress, leading to reduced grain yield and quality. Total RNA was extracted from developing seeds under stress and control (fully flooded) conditions and RNA-seq analysis was performed. These samples are a part of a bigger experiment analysing the responses of three contrasting rice cultivars (N22, Dular, Anjali) to combined heat and drought stress including different organs (developing seeds, flag leaves, flowering spikelets) and developmental stages (early grain filling, flowering) at the transcriptomic level.