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.
Project description:Cassava (Manihot esculenta) is one of the most important staple food crops worldwide. Its starchy tuberous roots supply over 800 million people with carbohydrates. Yet, surprisingly little is known about the processes involved in filling of those vital storage organs. A better understanding of cassava carbohydrate allocation and starch storage is key to improve storage root yield. In this work, we studied cassava morphology and phloem sap flow from source to sink using transgenic pAtSUC2::GFP plants, the phloem tracers esculin and 5(6)-carboxyfluorescein diacetate (CFDA), as well as several staining techniques. We show that cassava performs apoplasmic phloem loading in source leaves and symplasmic unloading into phloem parenchyma cells of tuberous roots. We demonstrate that vascular rays play an important role in radial transport from the phloem to xylem parenchyma cells in tuberous roots. Furthermore, enzymatic and proteomic measurements of storage root tissues confirmed high abundance and activity of enzymes involved in the sucrose synthase-mediated pathway and indicated that starch is stored most efficiently in the outer xylem layers of tuberous roots. Our findings represent a first basis for biotechnological approaches aimed at improved phloem loading and enhanced carbohydrate allocation and storage in order to increase tuberous root yield of cassava.
Project description:Transcriptome of cassava seedling were analysised in 7% PEG and 50 μmol of ABA by RNA-seq.The goal of this study was to compare the phenotypic and transcriptome differences between treatment and WT plants, and to analyze how treatment changed the expression patterns.
2020-08-22 | GSE156638 | GEO
Project description:RNA-Seq data of cassava tuberous roots under phytohormones treatment
Project description:External application of acetic acid has been recently reported to enhance the survival to drought in plants such as Arabidopsis, rapeseed, maize, rice and wheat, but the effects of acetic acid application on increased drought tolerance in woody plants such as a tropical crop “cassava” remain elusive. A molecular understanding of acetic acid-induced drought avoidance in cassava will contribute to the development of technology that can be used to enhance drought tolerance without resorting to transgenic technology or advancements in cassava cultivation. In the present study, morphological, physiological and molecular responses to drought were analyzed in cassava after the treatment with acetic acid. Results indicated that the acetic acid-treated cassava plants had a higher level of drought avoidance than water-treated, control plants. Specifically, higher leaf relative water content, and chlorophyll and carotenoid levels were observed as soils dried out during the drought treatment. Leaf temperatures in acetic acid-treated cassava plants were higher relative to leaves on plants pretreated with water and the increase of ABA content was observed in leaves of acetic acid-treated plants, suggesting that stomatal conductance and the transpiration rate in leaves of acetic acid-treated plants decreased to maintain relative water contents and avoid drought. Transcriptome analysis revealed that the acetic acid treatment increased the expression of ABA signaling-related genes, such as OPEN STOMATA 1 (OST1) and protein phosphatase 2C; as well as drought response and tolerance-related genes, such as outer membrane tryptophan-rich sensory protein (TSPO), and heat shock proteins. Collectively, the external application of acetic acid enhances drought avoidance in cassava through the upregulation of ABA signaling pathway genes and several stress response- and tolerance-related genes. These data support the idea that adjustments of the acetic acid application to plants is useful to enhance drought tolerance in order to minimize the growth inhibition in the agricultural field.
Project description:We developed a 60-mer oligonucleotide Agilent microarray representing about 20,000 cassava genes and applied it to expression profiling under drought stress. We demonstrated that our microarray is an useful tool for analyzing the cassava transcriptome and that it can be applied to various cassava species.
Project description:Investigation of whole transcriptome gene expression level during tuberous root formation and development in sweetpotato (Ipomoea batatas) cv. Guangshu 87 Identification of transcription factors (TFs) during tuberous root formation and development in sweetpotato (Ipomoea batatas) cv. Guangshu 87
Project description:Cassava is the most important root crop in the tropics but rapid post-harvest physiological root deterioration (PPD) is a major constraint to commercial cassava production. We used label-free quantitative proteomics to generate an extensive cassava root and PPD proteome. Over 2400 unique proteins were identified in the cassava root and nearly 300 proteins showed significant abundance regulation during PPD. A candidate gene for reducing PPD was identified from the regulated proteins with enzymatic assays and afterwards verified with a transgene approach. This demonstrates the relevance of proteomics approach for crop improvements.
Project description:ABA-signaling in disitinct root tissues is important for xylem phenotypes observed both under mock and ABA-treatment. We performed RNA-sequencing on Arabidopsis plants in which ABA-signalling is specifically blocked in the endodermis (J0571), the xylem (J1721) or the procambium (Q0990) to investigate the underlying transcriptomic changes.
2021-03-23 | GSE169363 | GEO
Project description:Rice root transcriptome after ABA treatment