scholarly journals A population based expression atlas provides insights into disease resistance and other physiological traits in cassava (Manihot esculenta Crantz)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alex C. Ogbonna ◽  
Punna Ramu ◽  
Williams Esuma ◽  
Leah Nandudu ◽  
Nicolas Morales ◽  
...  
Keyword(s):  
Differential Expression ◽  
Complex Traits ◽  
Expression Patterns ◽  
Research Work ◽  
Population Based ◽  
Mosaic Disease ◽  
Cassava Mosaic Disease ◽  
Soil Conditions ◽  
Manihot Esculenta Crantz ◽  
Expression Atlas

AbstractCassava, a food security crop in Africa, is grown throughout the tropics and subtropics. Although cassava can provide high productivity in suboptimal conditions, the yield in Africa is substantially lower than in other geographies. The yield gap is attributable to many challenges faced by cassava in Africa, including susceptibility to diseases and poor soil conditions. In this study, we carried out 3’RNA sequencing on 150 accessions from the National Crops Resources Research Institute, Uganda for 5 tissue types, providing population-based transcriptomics resources to the research community in a web-based queryable cassava expression atlas. Differential expression and weighted gene co-expression network analysis were performed to detect 8820 significantly differentially expressed genes (DEGs), revealing similarity in expression patterns between tissue types and the clustering of detected DEGs into 18 gene modules. As a confirmation of data quality, differential expression and pathway analysis targeting cassava mosaic disease (CMD) identified 27 genes observed in the plant–pathogen interaction pathway, several previously identified CMD resistance genes, and two peroxidase family proteins different from the CMD2 gene. Present research work represents a novel resource towards understanding complex traits at expression and molecular levels for the development of resistant and high-yielding cassava varieties, as exemplified with CMD.

scholarly journals A population based expression atlas provides insights into disease resistance and other physiological traits in cassava (Manihot esculenta Crantz)

2021 ◽  
Author(s):  
Alex C. Ogbonna ◽  
Punna Ramu ◽  
Esuma Williams ◽  
Leah Nandudu ◽  
Nicolas Morales ◽  
...  
Keyword(s):  
Differential Expression ◽  
Complex Traits ◽  
Expression Patterns ◽  
Research Work ◽  
Population Based ◽  
Mosaic Disease ◽  
Cassava Mosaic Disease ◽  
Soil Conditions ◽  
Manihot Esculenta Crantz ◽  
Expression Atlas

AbstractCassava, a food security crop in Africa, is grown throughout the tropics and subtropics. Although cassava can provide high productivity in suboptimal conditions, the yield in Africa is substantially lower than in other geographies. The yield gap is attributable to many challenges faced by cassava in Africa, including susceptibility to diseases and poor soil conditions. In this study, we carried out 3’RNA sequencing on 150 accessions from the National Crops Resources Research Institute, Ugandan for 5 tissue types, providing population-based transcriptomics resources to the research community in a web-based queryable cassava expression atlas. Differential expression and weighted gene co-expression network analysis were performed to detect 8,820 significantly differentially expressed genes (DEGs), revealing similarity in expression patterns between tissue types and the clustering of detected DEGs into 18 gene modules. As a confirmation of data quality, differential expression and pathway analysis targeting cassava mosaic disease (CMD) identified 27 genes observed in the plant-pathogen interaction pathway, several previously identified CMD resistance genes and two peroxidase family proteins different from the CMD2 gene. Present research work represents a novel resource towards understanding complex traits at expression and molecular levels for the development of resistant and high-yielding cassava varieties, as exemplified with CMD.

scholarly journals WRKY Transcription Factors in Cassava Contribute to Regulation of Tolerance and Susceptibility to Cassava Mosaic Disease through Stress Responses

Viruses ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1820
Author(s):  
Warren Freeborough ◽  
Nikki Gentle ◽  
Marie E. C. Rey
Keyword(s):  
Transcription Factors ◽  
Stress Responses ◽  
Regulatory Networks ◽  
Large Scale ◽  
Mosaic Disease ◽  
African Cassava Mosaic Virus ◽  
Cassava Mosaic Disease ◽  
Manihot Esculenta Crantz ◽  
Transcriptional Reprogramming ◽  
Negative Role

Among the numerous biological constraints that hinder cassava (Manihot esculenta Crantz) production, foremost is cassava mosaic disease (CMD) caused by virus members of the family Geminiviridae, genus Begomovirus. The mechanisms of CMD tolerance and susceptibility are not fully understood; however, CMD susceptible T200 and tolerant TME3 cassava landraces have been shown to exhibit different large-scale transcriptional reprogramming in response to South African cassava mosaic virus (SACMV). Recent identification of 85 MeWRKY transcription factors in cassava demonstrated high orthology with those in Arabidopsis, however, little is known about their roles in virus responses in this non-model crop. Significant differences in MeWRKY expression and regulatory networks between the T200 and TME3 landraces were demonstrated. Overall, WRKY expression and associated hormone and enriched biological processes in both landraces reflect oxidative and other biotic stress responses to SACMV. Notably, MeWRKY11 and MeWRKY81 were uniquely up and downregulated at 12 and 67 days post infection (dpi) respectively in TME3, implicating a role in tolerance and symptom recovery. AtWRKY28 and AtWRKY40 homologs of MeWRKY81 and MeWRKY11, respectively, have been shown to be involved in regulation of jasmonic and salicylic acid signaling in Arabidopsis. AtWRKY28 is an interactor in the RPW8-NBS resistance (R) protein network and downregulation of its homolog MeWRKY81 at 67 dpi in TME3 suggests a negative role for this WRKY in SACMV tolerance. In contrast, in T200, nine MeWRKYs were differentially expressed from early (12 dpi), middle (32 dpi) to late (67 dpi) infection. MeWRKY27 (homolog AtWRKY33) and MeWRKY55 (homolog AtWRKY53) were uniquely up-regulated at 12, 32 and 67 dpi in T200. AtWRKY33 and AtWRKY53 are positive regulators of leaf senescence and oxidative stress in Arabidopsis, suggesting MeWRKY55 and 27 contribute to susceptibility in T200.

scholarly journals First Report of East African Cassava Mosaic Begomovirus in Nigeria

Plant Disease ◽  
1999 ◽  
Vol 83 (4) ◽  
pp. 398-398 ◽  
Author(s):  
F. O. Ogbe ◽  
G. I. Atiri ◽  
D. Robinson ◽  
S. Winter ◽  
A. G. O. Dixon ◽  
...  
Keyword(s):  
Central Africa ◽  
Mosaic Disease ◽  
Sub Saharan Africa ◽  
Cassava Mosaic Disease ◽  
Enzyme Linked Immunosorbent Assay ◽  
East African ◽  
African Countries ◽  
Manihot Esculenta Crantz ◽  
Cross River State ◽  
Sub Saharan

Cassava (Manihot esculenta Crantz) is an important food crop in sub-Saharan Africa. One of the major production constraints is cassava mosaic disease caused by African cassava mosaic (ACMV) and East African cassava mosaic (EACMV) begomoviruses. ACMV is widespread in its distribution, occurring throughout West and Central Africa and in some eastern and southern African countries. In contrast, EACMV has been reported to occur mainly in more easterly areas, particularly in coastal Kenya and Tanzania, Malawi, and Madagascar. In 1997, a survey was conducted in Nigeria to determine the distribution of ACMV and its strains. Samples from 225 cassava plants showing mosaic symptoms were tested with ACMV monoclonal antibodies (MAbs) in triple antibody sandwich enzyme-linked immunosorbent assay (1). Three samples reacted strongly with MAbs that could detect both ACMV and EACMV. One of them did not react with ACMV-specific MAbs while the other two reacted weakly with such MAbs. With polymerase chain reaction (2), the presence of EACMV and a mixture of EACMV and ACMV in the respective samples was confirmed. These samples were collected from two villages: Ogbena in Kwara State and Akamkpa in Cross River State. Co-infection of some cassava varieties with ACMV and EACMV leads to severe symptoms. More importantly, a strain of mosaic geminivirus known as Uganda variant arose from recombination between the two viruses (2). This report provides evidence for the presence of EACMV in West Africa. References: (1) J. E. Thomas et al. J. Gen. Virol. 67:2739, 1986. (2) X. Zhou et al. J. Gen. Virol. 78:2101, 1997.

scholarly journals A Combined Nutrient/Biocontrol Agent Mixture Improve Cassava Tuber Yield and Cassava Mosaic Disease

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1650
Author(s):  
Kumar Neelakandan ◽  
Kalarani M. Karuppasami ◽  
Nageswari Karuppusamy ◽  
Kavitha P. Shanmugam ◽  
Pugalendhi Lakshmanan ◽  
...  
Keyword(s):  
Field Experiments ◽  
Tuber Yield ◽  
Biocontrol Agent ◽  
Foliar Spray ◽  
Nutrient Deficiency ◽  
Mosaic Disease ◽  
Cassava Mosaic Disease ◽  
Nutrient Deficiencies ◽  
Manihot Esculenta Crantz ◽  
Altered Lipid

Cassava (Manihot esculenta Crantz) is an important tropical root crop and a major dietary energy source for more than 500 million people. The major production constraints in cassava are the occurrence of nutrient deficiency and cassava mosaic disease (CMD). Hence to increase the cassava yield, it is critical to develop a technology to overcome the problems associated with nutrient deficiencies and CMD. Series of field experiments were conducted to evaluate and validate a new mixture containing biocontrol agent and nutrients on different genotypes and locations. The result indicated that foliar spray of combined nutrient/biocontrol agent mixture at 21 d interval from one to five-month after planting (MAP) had significantly decreased the incidence of nutrient deficiency symptom and CMD incidence resulting in an increased tuber yield. There were significant differences among the cassava genotypes for CMD reaction and foliar spray of combined nutrient/biocontrol agent mixture at 21 d interval from 1 to 5 MAP. The genotype H226 had lower CMD incidence and higher tuber yield. The multilocation trial indicated that foliar spray of combined nutrient/biocontrol agent mixture at 21 d interval from 1 to 5 MAP significantly improved the tuber yield (24%) and decreased the CMD incidence (65%) than unsprayed control. Metabolomic study indicates that foliar spray of combined nutrient/biocontrol agent mixture has altered lipid biosynthesis and metabolism, as evidenced by increased accumulation of octadecatrienoic acid (2.28-fold) trilinolein (126.3-fold) in combined nutrient/biocontrol agent mixture sprayed plants over unsprayed control. Overall, it is evident that foliar spray of combined nutrient/biocontrol agent mixture from 1 to 5 MAP has decreased CMD incidence and increased the tuber yield.

Effect of African cassava mosaic disease on morphological characteristics of cassava, Manihot esculenta (Crantz)

2015 ◽  
Vol 11 (2) ◽  
pp. 258-265
Author(s):  
TF Oyadiran ◽  
JA Osakwe
Keyword(s):  
Disease Incidence ◽  
Morphological Characteristics ◽  
Field Trials ◽  
Mosaic Disease ◽  
Cassava Mosaic Disease ◽  
Petiole Length ◽  
Manihot Esculenta Crantz ◽  
Key Word ◽  
Mechanized Agriculture ◽  
Number Of Branches

Field trials were conducted with 10 improved clones of cassava to study the effect of ACMD on their morphological characteristics. The clones used were: 97 / 4763, 97/2205, 91/02324, 98/0505, M98/0068, 96/1089A, 96/1632, M98/0040, 99/2123 and 97/0162. The parameters measured were plant height, leaf area, number of branches and petiole length. The research revealed differences within the clones for the parameters studied, these differences seemed to be mainly genetic, as they were not positively correlated to the disease incidence and severity. Based on the findings in this research the following recommendations were made. On the basis of their branching pattern, highly branched clones 97 / 2205, 97/4763 and 98 /0505 are recommended for selection. The heavy branches bear a lot of leaves or produce a thick canopy which helps to reduce the need for weeding, and also reduce the effect of loss of leaves that occur due to disease incidence. However, for industrial / mechanized agriculture, clones that are less branched should be selected as they are easier to harvest mechanically. Though there is disadvantage with their small leaf areas; the crops would have to be highly resistant to fungal attack which tends to cause leaf drop that will reduce leaf material for food / starch production (examples of less branching clones are, M98 / 0068, 96/1632,91/02324).Key Word: African Cassava Mosaic Disease (ACMD), Cassava Mosaic Virus.(CMV)

scholarly journals A New Type of Satellite associated with Cassava Mosaic Begomoviruses

2021 ◽  
Author(s):  
Catherine D. Aimone ◽  
Leandro De León ◽  
Mary M. Dallas ◽  
Joseph Ndunguru ◽  
José T. Ascencio-Ibáñez ◽  
...  
Keyword(s):  
Symptom Severity ◽  
Smallholder Farmers ◽  
Mosaic Disease ◽  
African Cassava Mosaic Virus ◽  
Cassava Mosaic Disease ◽  
Viral Diseases ◽  
Soil Conditions ◽  
Viral Dna ◽  
Single Stranded Dna ◽  
New Type

AbstractCassava mosaic disease (CMD), which is caused by single-stranded DNA begomoviruses, severely limits cassava production across Africa. A previous study showed that CMD symptom severity and viral DNA accumulation increase in cassava in the presence of a DNA sequence designated as SEGS-2 (sequence enhancing geminivirus symptoms). We report here that when SEGS-2 is co-inoculated with African cassava mosaic virus (ACMV) onto Arabidopsis thaliana, viral symptoms increase. Transgenic Arabidopsis with an integrated copy of SEGS-2 inoculated with ACMV also display increased symptom severity and viral DNA levels. Moreover, SEGS-2 enables Cabbage leaf curl virus (CaLCuV) to infect a geminivirus resistant Arabidopsis accession. Although SEGS-2 is related to cassava genomic sequences, an earlier study showed that it occurs as episomes and is packaged into virions in CMD-infected cassava and viruliferous whiteflies. We identified SEGS-2 episomes in SEGS-2 transgenic Arabidopsis. The episomes occur as both double-stranded and single-stranded DNA, with the single-stranded form packaged into virions. In addition, SEGS-2 episomes replicate in tobacco protoplasts in the presence, but not the absence, of ACMV DNA-A. SEGS-2 episomes contain a SEGS-2 derived promoter and an open reading frame with the potential to encode a 75-amino acid protein. An ATG mutation at the beginning of the SEGS-2 coding region does not enhance ACMV infection in Arabidopsis. Together, the results established that SEGS-2 is a new type of begomovirus satellite that enhances viral disease through the action of a SEGS-2 encoded protein that may also be encoded in the cassava genome.IMPORTANCECassava is an important root crop in the developing world and a food and income crop for more than 300 million African farmers. Cassava is rising in global importance and trade as the demands for biofuels and commercial starch increase. More than half of the world’s cassava is produced in Africa, where it is primarily grown by smallholder farmers, many of whom are from the poorest villages. Although cassava can grow under high temperature, drought and poor soil conditions, its production is severely limited by viral diseases. Cassava mosaic disease (CMD) is one of the most important viral diseases of cassava and can cause up to 100% yield losses. We provide evidence that SEGS-2, which was originally isolated from cassava crops displaying severe and atypical CMD symptoms in Tanzanian fields, is a novel begomovirus satellite that can compromise the development of durable CMD resistance.

scholarly journals Molecular-assisted selection for resistance to cassava mosaic disease in Manihot esculenta Crantz

2015 ◽  
Vol 72 (6) ◽  
pp. 520-527 ◽  
Author(s):  
Cátia Dias do Carmo ◽  
Maiane Suzarte da Silva ◽  
Gilmara Alvarenga Fachardo Oliveira ◽  
Eder Jorge de Oliveira
Keyword(s):  
Manihot Esculenta ◽  
Mosaic Disease ◽  
Cassava Mosaic Disease ◽  
Manihot Esculenta Crantz ◽  
Selection For ◽  
Molecular Assisted Selection

scholarly journals Genotypic Variability in Some Morpho-Physiological Traits in Different Environments and Their Relationship with Cassava (Manihot esculenta Crantz) Root Yield

2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Joseph Adjebeng-Danquah ◽  
Isaac Kwadwo Asante ◽  
Joseph Manu-Aduening ◽  
Richard Yaw Agyare ◽  
Vernon Edward Gracen ◽  
...  
Keyword(s):  
Block Design ◽  
Principal Component ◽  
Mosaic Disease ◽  
Physiological Traits ◽  
Cassava Mosaic Disease ◽  
Environment Interaction ◽  
Gge Biplot ◽  
Root Yield ◽  
Manihot Esculenta Crantz ◽  
Drought Tolerant

Cassava root yield under diverse environments is influenced by morpho-physiological traits that are in turn influenced by genotype, environment, and genotype × environment interaction (GEI). Most GEI analyses in cassava have been limited to root yield with less emphasis on stability of other yield-related traits. This study was carried out to assess the effect of GEI on some morpho-physiological traits in cassava and key traits that are useful for selection in different environments. The study utilized 20 cassava genotypes evaluated in six environments, namely, Fumesua 2013 and 2014, Nyankpala 2013 and 2014 (irrigation), and Nyankpala 2013 and 2014 (no irrigation). The genotypes were arranged in a randomized complete block design (RCBD) with three replications and assessed for a number of morpho-physiological traits, root yield and yield components. The data were subjected to analysis of variance using SAS statistical package. Subsequently, the GGE biplot was used to carry out genotype × environment, genotype × trait, and environment × trait interaction analyses to determine the specificity of genotypic performance and traits linked to particular environments. The results indicated significant (P<0.05) GEI effect on all traits except leaf temperature. The genotype × trait biplot analysis revealed closely related traits and those associated with root yield and genotypes that show weakness in these traits. Both environment × trait biplot and principal component analyses identified traits with higher discriminatory power among genotypes in various environments particularly in the dry environments. These can be used as secondary traits to select drought-tolerant genotypes. From this study, the GGE biplot was useful in identifying traits associated with specific genotypes in different environments to aid in selection. Moderate broad-sense heritability estimates werefound for storage root yield, harvest index, plant height, ratio of storage rootlength to girth, and cassava mosaic disease score indicating that progresscan be made through selection for these traits.

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