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:Cassava is a drought–resistant food crop in tropical and subtropical regions. Although cassava is a relatively drought-tolerant species, the development and yields are greatly affected by the adverse drought conditions. Information about molecular breeding will obtain by studying genetic regulatory mechanism. In this study, we demonstrate the drought-tolerant mechanisms in leaves of both cassava varieties(Xinxuan048 and KU50) by using RNA-Seq technique. 1,880 and 2,066 differentially expressed genes(DEGs) were induced by drought stress in leaves of KU50 and Xinxuan048, respectively. DEGs in the response to drought stress involve in many regulated pathways. ROS- and ABA-associated signaling pathways and photosynthesis-associated regulation are mainly elucidated. In addition, alternative splicing and ingle nucleotide polymorphism also involve in drought-stress responses in both cassava varieties, showing their important roles in response to drought stress in leaves. This study not only increases the understanding of physiological and molecular mechanisms to the drought response in cassava, but also lays a solid foundation on the breeding of drought-resistant varieties using molecular methods.
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:Full length long read transcript sequences were used as guides along with other multi-omics data to build gene model annotation of Cassava.
Project description:DNA Methylome and lncRNAome analysis provide insights into mechanism of genome-dosage effects in heterozygous autotetraploid cassava
Project description:Moderate stress acclimation provides immunity to stress by rewiring regulatory networks and inducing genes with protective functions in Cassava
Project description:Quant-Seq (3'-end sequencing technique) of mRNAs to identify the 3'-ends of transcripts to analyse the 3'-UTR that were used with other multi-omics data to build gene model annotation of Cassava.