Lysozyme inhibits postharvest physiological deterioration of cassava

Abstract: The objective of this work was to define procedures to assess the tolerance of cassava genotypes to postharvest physiological deterioration (PPD) and to microbial deterioration (MD). Roots of six cassava genotypes were evaluated in two experiments, during storage under different environmental conditions: high temperature and low soil moisture; or low temperature and high soil moisture. Roots were treated or not with fungicide (carbendazim) before storage. Genotype reactions to MD and PPD were evaluated at 0, 2, 5, 10, 15, 20, and 30 days after harvest (DAH), in the proximal, medial, and distal parts of the roots. A diagrammatic scale was proposed to evaluate nonperipheral symptoms of PPD. Fungicide treatment and root position did not influence PPD expression; however, all factors had significant effect on MD severity. Genotypes differed as to their tolerance to PPD and MD. Both deterioration types were more pronounced during periods of higher humidity and lower temperatures. The fungicide treatment increased root shelf life by reducing MD severity up to 10 DAH. Whole roots showed low MD severity and high PPD expression up to 10 DAH, which enabled the assessment of PPD without significant interference of MD symptoms during this period.

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Cassava shrunken-2 homolog MeAPL3 determines storage root starch and dry matter content and modulates storage root postharvest physiological deterioration

Plant Molecular Biology ◽

10.1007/s11103-020-00995-z ◽

2020 ◽

Cited By ~ 1

Author(s):

Getu Beyene ◽

Raj Deepika Chauhan ◽

Jackson Gehan ◽

Dimuth Siritunga ◽

Nigel Taylor

Keyword(s):

Dry Matter ◽

Starch Content ◽

Matter Content ◽

Dry Matter Content ◽

Dry Matter Accumulation ◽

Storage Root ◽

Storage Roots ◽

Leaf Phenotype ◽

Root Starch ◽

Postharvest Physiological Deterioration

Abstract Key message Among the five cassava isoforms (MeAPL1–MeAPL5), MeAPL3 is responsible for determining storage root starch content. Degree of storage root postharvest physiological deterioration (PPD) is directly correlated with starch content. Abstract AGPase is heterotetramer composed of two small and two large subunits each coded by small gene families in higher plants. Studies in cassava (Manihot esculenta) identified and characterized five isoforms of Manihot esculenta ADP-glucose pyrophosphorylase large subunit (MeAPL1–MeAPL5) and employed virus induced gene silencing (VIGS) to show that MeAPL3 is the key isoform responsible for starch and dry matter accumulation in cassava storage roots. Silencing of MeAPL3 in cassava through stable transgenic lines resulted in plants displaying significant reduction in storage root starch and dry matter content (DMC) and induced a distinct phenotype associated with increased petiole/stem angle, resulting in a droopy leaf phenotype. Plants with reduced starch and DMC also displayed significantly reduced or no postharvest physiological deterioration (PPD) compared to controls and lines with high DMC and starch content. This provides strong evidence for direct relationships between starch/dry matter content and its role in PPD and canopy architecture traits in cassava.

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The Class III Peroxidase (POD) Gene Family in Cassava: Identification, Phylogeny, Duplication, and Expression

International Journal of Molecular Sciences ◽

10.3390/ijms20112730 ◽

2019 ◽

Vol 20 (11) ◽

pp. 2730 ◽

Cited By ~ 5

Author(s):

Chunlai Wu ◽

Xupo Ding ◽

Zehong Ding ◽

Weiwei Tie ◽

Yan Yan ◽

...

Keyword(s):

Stress Responses ◽

Transcriptional Control ◽

Tandem Duplication ◽

Target Genes ◽

Hormone Signaling ◽

Class Iii ◽

Motif Analysis ◽

Transcriptional Changes ◽

Postharvest Physiological Deterioration ◽

Class Iii Peroxidase

The class III peroxidase (POD) enzymes participate in plant development, hormone signaling, and stress responses. However, little is known about the POD family in cassava. Here, we identified 91 cassava POD genes (MePODs) and classified them into six subgroups using phylogenetic analysis. Conserved motif analysis demonstrated that all MePOD proteins have typical peroxidase domains, and gene structure analysis showed that MePOD genes have between one and nine exons. Duplication pattern analysis suggests that tandem duplication has played a role in MePOD gene expansion. Comprehensive transcriptomic analysis revealed that MePOD genes in cassava are involved in the drought response and postharvest physiological deterioration. Several MePODs underwent transcriptional changes after various stresses and related signaling treatments were applied. In sum, we characterized the POD family in cassava and uncovered the transcriptional control of POD genes in response to various stresses and postharvest physiological deterioration conditions. These results can be used to identify potential target genes for improving the stress tolerance of cassava crops.

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Development of a diagrammatic scale for the evaluation of postharvest physiological deterioration in cassava roots

Pesquisa Agropecuária Brasileira ◽

10.1590/s0100-204x2015000800004 ◽

2015 ◽

Vol 50 (8) ◽

pp. 658-668 ◽

Cited By ~ 1

Author(s):

Marcela Tonini Venturini ◽

Leandro Ribeiro dos Santos ◽

Eder Jorge de Oliveira

Keyword(s):

Postharvest Physiological Deterioration ◽

Different Levels ◽

Diagrammatic Scale

Abstract:The objective of this work was to develop a scale to assess the severity of postharvest physiological deterioration (PPD) of cassava roots, and to validate this scale for accuracy and reproducibility estimates. A diagrammatic scale (0 to 100%) for the damaged roots was analyzed according to precision, accuracy, and reproducibility. Seven evaluators (four with experience and three without it) quantified the PPD severity, with or without the scale, considering 150 roots with different levels of PPD. Without and with the use of the scale, respectively, the inexperienced evaluators obtained coefficients of determination (R2) from 0.76 to 0.86 and 0.87 to 0.92, and the experienced evaluators obtained R2 from 0.90 to 0.96 and 0.96 to 0.97. The values of the intercept (a) obtained by both the experienced and inexperienced evaluators who did not use the scale were all significant, while after using the scale, only two evaluators got values that were not significantly different from one. Evaluation reproducibility between the evaluators ranged from 0.61 to 0.91 for the inexperienced ones and from 0.83 to 0.95 for the experienced ones. The proposed diagrammatic scale was considered appropriate to estimate the severity of PPD in cassava roots, and can be used to identify sources of tolerance to postharvest deterioration.

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