Project description:In response to infection, viral genomes are processed by Dicer-like (DCL) ribonuclease proteins into viral small RNAs (vsRNAs) of discrete sizes. vsRNAs are then used as guides for silencing the viral genome. The profile of vsRNAs produced during the infection process has been extensively studied for some group of viruses. However, nothing is known for members of the economically important family Luteoviridae, a group of phloem-restricted viruses. Here, the population of vsRNAs from cotton plants infected with Cotton leafroll dwarf virus (CLRDV), a member of the genus Polerovirus, family Luteoviridae, is characterized.Deep sequencing of small RNAs (sRNAs) from CLRDV-infected cotton leaves was performed. Results showed 21-nt to 24-nt long vsRNAs matching all the viral genome, with a higher frequency of matches in the 3â region. Equivalent amounts of sense and antisense vsRNAs were found, and the 22-nt long small RNA class was the most prominent one. Looking for cotton Dcl transcripts levels during infection, we could observe that Dcl4 seems to be up-regulated, while Dcl2 seems to be down-regulated.This is the first report on the profile of sRNAs coming from a plant infected with a member of the family Luteoviridae. Our sequence data strongly suggest that virus-derived double-stranded RNA functions as one of the main precursors of vsRNAsOur results indicate that secondary structures of the viral RNAs are not the main source of the viRNAs observed, as suggested for other viruses. Judging by the profiled size classes, all cotton DCLs might be working to silence the virus. The possible causes for the unexpected high accumulation of 22-nt viRNAvsRNAs are discussed. CLRDV is the causal agent of worldwide cotton pathology named Cotton blue disease. Our results are an important contribution for understanding the molecular mechanisms involved in this and related diseases.
Project description:Global gene expression was compared between roots of cotton plants (variety Sicot 71) flooded for 4 hours and roots of unflooded cotton plants. Global gene expression was also compared between leaves of cotton plants (variety Sicot 71) flooded for 24 hours and leaves of unflooded cotton plants. Waterlogging stress causes yield reductions in cotton (Gossypium hirsutum L.). A major component of waterlogging stress is the lack of oxygen available to submerged tissues. While changes in expressed protein, gene transcription and metabolite levels have been studied in response to low oxygen stress, little research has been done on molecular responses to waterlogging in cotton. We assessed cotton growth responses to waterlogging and assayed global gene transcription responses in root and leaf cotton tissues of partially submerged plants. Waterlogging causes significant reductions in stem elongation, shoot mass, root mass, and leaf number. At the global gene expression level waterlogging significantly alters the expression of 1012 genes (4.2% of genes assayed) in root tissue as early as 4h after flooding. Many of these genes are associated with cell wall modification and growth pathways, glycolysis, fermentation, mitochondrial electron transport and nitrogen metabolism. Waterlogging of plant roots also altered global leaf gene expression, significantly changing the expression of 1305 genes (5.4% of genes assayed) after 24h of flooding. Genes associated with cell wall growth and modification, tetrapyrrole synthesis, hormone response, starch metabolism and nitrogen metabolism were affected in leaf tissues of waterlogged plants. Implications of these results for the development of waterlogging tolerant cotton are discussed. Keywords: Stress Response
Project description:Cotton seeds (Gossypium hirsutum cv. CCRI12) were grown in a growth chamber under 29/25°C temperature and a 16:8 h light:dark cycle, and water was added every two days. All plants were used in experiments at the 6-7 fully expanded true leaf stage, which occurred 5-6 weeks after sowing. Cotton bollworm (CBW; Helicoverpa armigera) larvae were reared on an artificial diet and maintained at 27 ± 2°C, 75 ± 10% relative humidity, and 14:10 h light:dark in the laboratory. For insect treatment, seven H. armigera larvae (third instars) were placed on a group of three plants, which were kept within plastic bags (30 × 40 cm), until time of harvest, with samples for each time point maintained separately. Undamaged plants maintained under the same conditions were used as controls. Cotton leaves from control plants and plants exposed to H. armigera were harvested at 6 h, 12 h, 24 h, and 48 h after onset of herbivory. For each treatment group and time point, cotton leaves were harvested from the three plants per treatment group and flash frozen in liquid nitrogen. For each time point, three replicate treatments and controls were performed. For insect treatment, seven H. armigera larvae (third instars) were placed on a group of three plants, which were kept within plastic bags (30 × 40 cm), until time of harvest, with samples for each time point maintained separately. Undamaged plants maintained under the same conditions were used as controls. Cotton leaves from control plants and plants exposed to H. armigera were harvested at 6 h, 12 h, 24 h, and 48 h after onset of herbivory. For each treatment group and time point, cotton leaves were harvested from the three plants per treatment group and flash frozen in liquid nitrogen. For each time point, three replicate treatments and controls were performed.
2016-01-01 | GSE62158 | GEO
Project description:RNA-seq data for cotton NAC4 transgenic plants
| PRJNA985099 | ENA
Project description:RNA-seq data for cotton LTP4 transgenic plants
| PRJNA947260 | ENA
Project description:RNA-seq data for cotton GbTCP20-silenced plants