Project description:microRNAs can play a crucial role in stress response in plants, including biotic stress. Some miRNAs are known to respond to bacterial infection. This work has addressed the role of miRNAs in Manihot esculenta (cassava)-Xanthomonas axonopodis pv. manihotis (Xam) interaction. Illumina sequencing was used for analyzing small RNA libraries from cassava tissue infected and non-infected with Xam. Cassava variety MBRA685 (resistant to Xam-CIO151) Six-week-old plants were inoculated with 36h-old cultures of the aggressive Xanthomonas axonopodis pv. manihotis strain CIO151 in both leaves and stems.
Project description:Phytomonas are a large and diverse sub-group of plant-infecting trypanosomatids that are relatively poorly understood. Little is known of their biology or how they have adapted to life inside plants. This study sequenced the genome of the Cassava (Manihot esculenta) infecting species Phytomonas francai to provide additional genome resources and new insight into the biology of this poorly understood group of organisms.
Project description:microRNAs can play a crucial role in stress response in plants, including biotic stress. Some miRNAs are known to respond to bacterial infection. This work has addressed the role of miRNAs in Manihot esculenta (cassava)-Xanthomonas axonopodis pv. manihotis (Xam) interaction. Illumina sequencing was used for analyzing small RNA libraries from cassava tissue infected and non-infected with Xam. Cassava variety MBRA685 (resistant to Xam-CIO151) Six-week-old plants were inoculated with 36h-old cultures of the aggressive Xanthomonas axonopodis pv. manihotis strain CIO151 in both leaves and stems. Leaves were inoculated by piercing six holes in the mesophyll and placing a 5µL drop of a liquid Xam-MgCl2 culture calibrated at OD600nm = 0.002 (1 x108cfu/ml). Two leaflets per leaf and three leaves per plant were inoculated. Stems were inoculated by puncture in the stems as described previously (24). At least three plants per collection time were inoculated. Leaves and stems were collected from inoculated plants (0 hours post inoculation -hpi, 6hpi, 24hpi, 2 days post-inoculation -dpi, 5dpi, 7dpi and 15dpi) and non-inoculated plants. RNA extractions were made using a LiCl-acid phenol:chloroform method.
Project description:Cassava (Manihot esculenta) is the food security crop that feeds approximately 800 million people worldwide. Although this crop displays high productivity under drought and poor soil conditions, it is susceptible to disease, postharvest deterioration and the roots contain low nutritional content. Cassava improvement programs are focused on addressing these constraints but are hindered by the crop’s high heterozygosity, difficulty in synchronizing flowering, low seed production and a poor understanding of the physiology of this plant. Among the major food crops, cassava is unique in its ability to develop massive, underground storage roots. Despite the importance of these structures, their basic physiology remains largely unknown, especially the molecular genetic basis of storage root development. Similarly, in cassava, the favored target tissue for transgene integration and genome editing is a friable embryogenic callus (FEC). Little is known concerning gene expression in this tissue, or its relatedness to the somatic organized embryogenic structures (OES) from which it originates. Here, we provide molecular identities for eleven cassava tissue types through RNA sequencing and develop an open access, web-based interface for further interrogation of the data. Through this dataset, we report novel insight into the physiology of cassava and identify promoters able to drive specified tissue expression profiles. The information gained from this study is of value for both conventional and biotechnological improvement programs.
2016-06-07 | GSE82279 | GEO
Project description:Haplotype-resolved genome sequence of Cassava (Manihot esculenta) cultivar COL40
Project description:Tuberous root formation is a complex process consisting of phase changes as well as cell division and elongation for radial growth. We performed an integrated analysis to clarify the relationships among metabolites, phytohormones, and gene transcription during tuberous root formation in cassava (Manihot esculenta Crantz). We also confirmed the effects of the auxin (AUX), cytokinin (CK), abscisic acid (ABA), jasmonic acid (JA), gibberellin (GA), brassinosteroid (BR), salicylic acid (SA), and indole-3-acetic acid conjugated with aspartic acid (IAAsp) on tuberous root development. An integrated analysis of metabolites and gene expression indicated the expression levels of several genes encoding enzymes involved in starch biosynthesis and sucrose metabolism are up-regulated during tuberous root development, which is consistent with the accumulation of starch, sugar phosphates, and nucleotides. An integrated analysis of phytohormones and gene transcripts revealed a relationship among AUX signaling, CK signaling, and BR signaling, with AUX, CK, and BR inducing tuberous root development. In contrast, ABA and JA inhibited tuberous root development. These phenomena might represent the differences between stem tubers (e.g., potato) and root tubers (e.g., cassava). On the basis of these results, a phytohormonal regulatory model for tuberous root development was constructed. This model may be useful for future phytohormonal studies involving cassava.