Project description:The aim of this study was to determine the changes in gene expression of rice root tips when they came in to contact with a hard layer (60% wax layer). Three categories of root tips were sampled; tips before the hard layer, tips that had come into contact with the hard layer and root tips which had buckled after coming into contact with the hard layer. Two genotypes (Azucena and Bala) that vary in there ability to penetrate a hard layer were selected for a genotype comparison of gene expression at the hard layer. Keywords: Genotype comparison, root impedance response
Project description:The aim of this study was to determine the changes in gene expression of rice root tips when they came in to contact with a hard layer (60% wax layer). Three categories of root tips were sampled; tips before the hard layer, tips that had come into contact with the hard layer and root tips which had buckled after coming into contact with the hard layer. Two genotypes (Azucena and Bala) that vary in there ability to penetrate a hard layer were selected for a genotype comparison of gene expression at the hard layer. Experiment Overall Design: A chamber with the internal dimensions of 10 x 5 x 25cm consisting of a glass back, Perspex front and aluminium spacers with an open bottom and top was set at an angle of 15o in a large sand filled tray and filled up to 19.5 cm with dry sand. The sand was watered with nutrient solution, the sand was levelled and then a 5mm thick 60% wax layer (prepared using a ratio of 3:2 (w/w) of pastillated paraffin wax / white soft wax) was poured on the sand. Once the wax layer had set, two small holes were placed at the back of the wax layer to allow water drainage and water exchange via capillary action. The chamber was then filled up with more dry sand, and then watered using nutrient solution. Nutrient solution was then added to the large tray which the chamber had been placed; this was regularly topped up and allowed the watering of the chamber by capillary action. Light was eliminated from the chambers using white (exterior face)/black (interior face) plastic sheeting. Experiment Overall Design: Azucena and Bala seeds were surface sterilized with 1% (v/w) sodium hypochlorate for 5 minutes, then rinsed thoroughly three times with water and then germinated on moist tissue paper for 48 hours at 37oC. A single germinated seed was then sown 1 cm below the surface of the sand in each chamber. Experiment Overall Design: The plants were grown in a controlled environment room with a 12 hour day and night, with a day temperature of 30oC and a night temperature of 24oC with 300 µmol m-2 s-1 PAR. After 24 days the chamber was dismantled and the root tips of 5 mm length were harvested from Azucena plants for subsequent RNA extractions from the three categories as follows; a) roots which were between 5-10 mm above the wax layer; b) roots at the wax layer; c) roots which had buckled at the wax layer and grown 7-10 mm after buckling. From Bala plants, only root tips at the layer were harvested. Experiment Overall Design: Each condition was indsependently replicated 3 times.
Project description:Gene expression profile of response to auxin at 3 h after treatment in rice root tips: IR64 (loss-of-function of DRO1 type) vs Near-isogenic line homozygous for the Kinandang Patong allele of DRO1 in an IR64 genetic background (Dro1-NIL; gain-of-function of DRO1 type) We used two rice varieties, IR64 and near-isogenic line homozygous for the Kinandang Patong allele of DRO1 in an IR64 genetic background (Dro1-NIL). We performed comprehensive microarray analysis of rice root tips with auxin treatment (3h) and pre-treatment (0h) in IR64 and Dro1-NIL. Seedling root tips of IR64 and Dro1-NIL were treated with 10 M-BM-5M 2,4-D. n = 3 biological repeats (15 seedlings per repeat).
Project description:Phosphate starvation/sufficient rice seedling, root or shoot Pi-starvation or Pi-sufficient stresses responsible rice genes, including previously unannotated genes were identified by Illumina mRNA-seq technology. 53 million reads from Pi-starvation or Pi-sufficient root or shoot tissues were uniquely mapped to the rice genome, and these included 40574 RAP3 transcripts in root and 39748 RAP3 transcripts in shoot. We compared our mRNA-seq expression data with that from Rice 44K oligomicroarray, and about 95.5% (root) and 95.4% (shoot) transcripts supported by the array were confirmed expression both by the array and by mRNA-seq, Moreover, 11888 (root) and 11098 (shoot) RAP genes which were not supported by array, were evidenced expression with mRNA-seq. Furthermore, we discovered 8590 (root) and 8193 (shoot) previously unannotated transcripts upon Pi-starvation and/or Pi-sufficient.
Project description:A biological phenomenon in which hybrids exhibit superior phenotypes from its parental inbred lines known as heterosis, has been widely exploited in plant breeding and extensively used in crop improvement. Hybrid rice has immense potential to increase yield over other rice varieties and hence is crucial in meeting increasing demand of rice globally. Moreover, the molecular basis of heterosis is still not fully understood and hence it becomes imperative to unravel its genetic and molecular basis. In this context, RNA sequencing technology (RNA-Seq) was employed to sequence transcriptomes of two rice hybrids, Ajay and Rajalaxmi, their parental lines, CRMS31A (sterile line, based on WA-CMS) and CRMS32A (sterile line based on Kalinga-CMS) respectively along with the common restorer line of both hybrids, IR-42266-29-3R at two critical rice developmental stages viz., panicle initiation (PI) and grain filling (GF). Identification of differentially expressed genes (DEGs) at PI and GF stages will further pave the way for understanding heterosis. In addition, such kind of study would help in better understanding of heterosis mechanism and genes up-regulated and down-regulated during the critical stages of rice development for higher yield.
Project description:affy_meloidogyne_rice - affy_meloidogyne_rice - Plant-parasitic nematodes cause profound economic losses to global agriculture with the obligate sedentary endoparasitic varieties; amongst them the cyst and Root Knot Nematode (RKN) species are the most damaging. Meloidogyne graminicola is a RKN mainly found in the monocotyledous plants. In the compatible interaction with Oryza sativa, M. graminicola induces the characteristic formation of hook-like galls resulting from the redifferentiation of root cells into multinucleate giant cells. In order to understand the global transcriptome changes occurring during infection, several recent microarray studies on root knots have demonstrated complex changes in host plant gene expression in response to infection. However, to our knowledge, all these transcriptome studies were performed on dicotyledous plants. A histological study enabled us to observe hyperplasia and hypertrophy of the surrounding cells leading to the formation of hook-like galls. We also investigated the plant response to M. graminicola by carrying out a global analysis of gene expression during gall formation in rice, using giant cell-enriched root tissues at an early stage (2dpi) and a latter stage (4dpi) of gall development.-Oryza sativa (var. Nipponbare) seedlings were grown on 6 cm3 SAP substrate completed with diluted Hoaglands solution (Reversat et al., 1999). Culture units were placed in a growth chamber illuminated with fluorescent tubes 9/24 h and maintained at 23°C for 5 days before being inoculated with a 100 J2-stage juveniles M. graminicola. One day after inoculation (dai), the rice seedlings were immersed in de-ionised water to remove all J2s that had not penetrated the roots and allowing synchronization of the infection. Each seedling was transferred to a hydroponic mini chamber (Reversat et al., 2004). Sampling was performed at 2 and 4 dai and each of them contained galls from 70 infected plants, they were then hand-dissected, frozen in liquid-nitrogen and stored at -80°C. As reference samples, uninfected meristematic root fragments were dissected from seedlings grown under the same conditions. Each sample was replicated 3 times. Keywords: normal vs disease comparison,time course
Project description:affy_meloidogyne_rice - affy_meloidogyne_rice - Plant-parasitic nematodes cause profound economic losses to global agriculture with the obligate sedentary endoparasitic varieties; amongst them the cyst and Root Knot Nematode (RKN) species are the most damaging. Meloidogyne graminicola is a RKN mainly found in the monocotyledous plants. In the compatible interaction with Oryza sativa, M. graminicola induces the characteristic formation of hook-like galls resulting from the redifferentiation of root cells into multinucleate giant cells. In order to understand the global transcriptome changes occurring during infection, several recent microarray studies on root knots have demonstrated complex changes in host plant gene expression in response to infection. However, to our knowledge, all these transcriptome studies were performed on dicotyledous plants. A histological study enabled us to observe hyperplasia and hypertrophy of the surrounding cells leading to the formation of hook-like galls. We also investigated the plant response to M. graminicola by carrying out a global analysis of gene expression during gall formation in rice, using giant cell-enriched root tissues at an early stage (2dpi) and a latter stage (4dpi) of gall development.-Oryza sativa (var. Nipponbare) seedlings were grown on 6 cm3 SAP substrate completed with diluted Hoaglands solution (Reversat et al., 1999). Culture units were placed in a growth chamber illuminated with fluorescent tubes 9/24 h and maintained at 23°C for 5 days before being inoculated with a 100 J2-stage juveniles M. graminicola. One day after inoculation (dai), the rice seedlings were immersed in de-ionised water to remove all J2s that had not penetrated the roots and allowing synchronization of the infection. Each seedling was transferred to a hydroponic mini chamber (Reversat et al., 2004). Sampling was performed at 2 and 4 dai and each of them contained galls from 70 infected plants, they were then hand-dissected, frozen in liquid-nitrogen and stored at -80°C. As reference samples, uninfected meristematic root fragments were dissected from seedlings grown under the same conditions. Each sample was replicated 3 times. Keywords: normal vs disease comparison,time course 9 arrays - rice
Project description:5 leaves old rice plantlets were infected with Magnaporthe grisea spores and zero, two hours and twenty four houres after infection samples were collected
Project description:In this study, we analyzed the early response of two rice cultivars to infection by RSV (Rice stripe virus) and its carrier at the transcriptome level using next-generation deep-sequencing techniques. We investigated the alteration in gene expression between a disease-resistant cultivar and a susceptible cultivar before and after inoculation with RSV by co-culturing with Laodelphax striatellus for 48 h. Our study provides insight at the molecular level into the mechanism of development of rice stripe disease, which contributes to our understanding of the rice-RSV interaction.
Project description:In this study, we used RNA-Seq to understand the mechanisms of Cd toxicity, cellular detoxification and protection pathways in response to Cd in rice roots. To gain additional insight into the rice transcriptomic response to environmental Cd stress, 15-day-old rice seedlings were treated with 10 or 100 μM solutions of Cd2+, or without Cd (control), for 24 h, at which point root samples were harvested and labeled as Cd+, Cd++, and control, respectively. These samples were used for 101 bp paired-end (PE) deep sequencing on an Illumina HiSeq 2500 platform.