Explore the vast range of titles available.

To control mango postharvest deterioration, an edible coating based on pectin, glycerol, and oregano essential oil (OEO) was developed using a three‐step process involving optimization, validation, and comparison with a commercial fungicide. An extreme vertices mixture design approach was initially used to optimize the pectin, glycerol, and OEO concentrations in the coating formulation. We evaluated the impact of the coating components on the respiration rate, quality parameters, and anthracnose disease of mangoes. The optimal coating composition was 3.91% (w/v) pectin, 0.57% (w/v) glycerol, and 0.52% (w/v) OEO, with a desirability value of 0.8998. Model validation demonstrated that the measured values for all parameters fit the prediction interval of 95%, and the relative error varied between 0.88% and 12.28%. Validation experiments of the optimal coating compared to untreated mango and mango treated with a commercial fungicide showed that the optimal coating delayed ripening and effectively controlled the incidence of anthracnose for 18 days at 14°C and 85% relative humidity. This study develops a pectin, glycerol, and oregano essential oil‐based coating for mango preservation, considering the limited options of postharvest treatments in producing countries and the growing demand for natural alternatives. This innovative method resulted in a coating that effectively delayed mango ripening and controlled anthracnose disease, presenting a viable alternative for mango preservation.

Protein phosphorylation modification plays a role in cells’ response to oxidative stress, a key factor leading to postharvest browning of Flammulina filiformis. However, the molecular mechanism by which protein phosphorylation contributes to postharvest browning of F. filiformis remains unclear. This study aimed to characterize the basal phosphoproteomic landscapes associated with variations in different browning phenotypes of F. filiformis. Using data-independent acquisition (DIA) mass spectrometry, we comprehensively profiled the phosphorylation dynamics in susceptible-to-browning (SB) and resistant-to-browning (RB) cultivars at harvest and after 24 h storage. We identified 84,244 phosphorylation sites on 4494 phosphoproteins, with the SB cultivar displaying more altered sites (21,195) than the RB (16,087). Functional enrichment analysis revealed that the differential phosphorylation was significantly implicated in kinases and energy metabolism pathways. Notably, the SB cultivar exhibited a more pronounced phosphorylation profile on key proteins involved in ATP synthesis and glycolysis. Protein–protein interaction (PPI) network analysis further indicated a kinase-mediated regulatory network targeting core energy metabolism components, including ATP synthase and 6-phosphofructokinase. This distinct phosphosignature in the SB cultivar correlated with its more severe browning phenotype and a sharper decline in ATP content during storage. Our findings suggest that divergent phosphorylation-mediated regulation of energy metabolism is strongly associated with the differential postharvest browning susceptibility between these two cultivars, providing a valuable molecular resource for future functional studies.

Key messageAmong 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.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.

One of the major problems for cassava is the rapid deterioration after harvesting cassava tuberous roots, which limits the possibilities for production and distribution of cassava in the world. Postharvest deterioration is an inherent problem for cassava since wounding and mechanical damage of the tuberous roots cannot be prevented during harvesting, which includes postharvest physiological deterioration (PPD) and secondary deterioration. To date, the molecular mechanism and biochemical pathways of PPD are poorly understood. The aim of this project, which is focusing on the early stages (first 72 hrs), is to gain molecular insight and identify important metabolic pathways during the process of PPD in cassava tuberous roots. Finally by reverse genetic approaches to delay or even prevent the process of PPD in cassava tuberous roots. By using a new RNA fingerprinting method, called cDNA-AFLP, we have screened more than 6,000 TDFs (Transcript Derived Fragments) via up to 100 primer combinations during the early process of PPD in cassava. Only 10% of the TDFs are developmentally regulated, while the other90% are expressed throughout the process of PPD in cassava tuberous roots. Furthermore, in order to set up a functional catalogue of differentially expressed genes during PPD, 70 TDFs were selected and isolated based on their expression patterns, which were either up-regulated,down-regulated or transiently induced. Around 40 of these TDFs were found to be similar with known genes in databases. The other 30 TDFs were present mostly genes without known function. Through data analysis,it is shown that important biochemical and physiological processes, such as notably oxygen stress, carbohydrate metabolism, protein metabolism and phenolic compounds synthesis, are involved in PPD in cassava tuberous roots.[PUBLICATION ABSTRACT]

The basic helix-loop-helix (bHLH) proteins are a large superfamily of transcription factors, and play a central role in a wide range of metabolic, physiological, and developmental processes in higher organisms. However, systematic investigation of bHLH gene family in cassava ( Manihot esculenta Crantz) has not been reported. In the present study, we performed a genome-wide survey and identified 148 MebHLH s genes were unevenly harbored in 18 chromosomes. Through phylogenetic analyses along with Arabidopsis counterparts, these MebHLHs genes were divided into 19 groups, and each gene contains a similar structure and conserved motifs. Moreover, many cis -acting regulatory elements related to various defense and stress responses showed in MebHLH genes. Interestingly, transcriptome data analyses unveiled 117 MebHLH genes during postharvest physiological deterioration (PPD) process of cassava tuberous roots, while 65 MebHLH genes showed significantly change. Meanwhile, the relative quantitative analysis of 15 MebHLH genes demonstrated that they were sensitive to PPD, suggesting they may involve in PPD process regulation. Cyanogenic glucosides (CGs) biosynthesis during PPD process was increased, silencing of MebHLH72 and MebHLH114 showed that linamarin content was significantly decreased in the leaves. To summarize, the genome-wide identification and expression profiling of MebHLH candidates pave a new avenue for uderstanding their function in PPD and CGs biosynthesis, which will accelerate the improvement of PPD tolerance and decrease CGs content in cassava tuberous roots.

Melatonin plays important roles in various aspects of biological processes. However, it is less known on the effects and mechanism of melatonin on the postharvest physiological deterioration (PPD) process of cassava, which largely restricts the potential of cassava as a food and industrial crop. In this study, we found that exogenous application of melatonin significantly delayed PPD of cassava tuberous roots by reducing H2O2 content and improving activities of catalase and peroxidase. Moreover, 3425 differentially expressed genes by melatonin during the PPD process were identified by transcriptomic analysis. Several pathways were markedly affected by melatonin treatments, including metabolic-, ion homeostasis-, and enzyme activity-related processes. Further detailed analysis revealed that melatonin acted through activation of ROS-scavenging and ROS signal transduction pathways, including antioxidant enzymes, calcium signaling, MAPK cascades, and transcription factors at early stages. Notably, the starch degradation pathway was also activated at early stages, whereas it was repressed by melatonin at middle and late stages, thereby indicating its regulatory role in starch metabolism during PPD. Taken together, this study yields new insights into the effect and underlying mechanism of melatonin on the delay of PPD and provides a good strategy for extending shelf life and improvement of cassava tuberous roots.

Cassava is one of the most versatile tuberous-root crops on Earth. However, the postharvest storage properties of cassava tuberous root mean that it is perishable through a process known as postharvest physiological deterioration (PPD), which seriously affects its starch quality. Therefore, a comprehensive understanding of the transcriptional regulatory activity of cassava against the PPD response is necessary in order to extract key molecular mechanisms related to PPD tolerance. In this study, we found that RYG1 tuberous roots showed delayed PPD compared to those of SC8. In addition, RYG1 roots maintained a more stable cell wall structure after storage than those of SC8. The transcriptome changes in tuberous roots were analyzed for both RYG1 and SC8 after 21 days of storage (SR and SS) compared to fresh (FR and FS) by the RNA-Seq method. The total number of differentially expressed genes (DEGs) in the various comparisons of these four samples ranged from 68 to 3847. Of these, a total of 2008 co-DEGs in SR vs. SS were shared by either SR vs. FR or SS vs. FS. GO and KEGG enrichment analysis revealed that upregulated co-DEGs in SR vs. SS were mainly enriched in photosynthesis, protein processing, hormone and cutin, suberine and wax biosynthesis. By contrast, the downregulated co-DEGs were mainly related to cell wall organization, starch and sucrose metabolism, galactose metabolism, phenylpropanoid biosynthesis, diterpenoid biosynthesis, cysteine and methionine metabolism and flavonoid biosynthesis. The protein–protein interaction (PPI) networks of the co-DEGs showed a complex interaction of genes in different pathways, and 16 hub genes were characterized to have a degree in excess of 15, among which eight genes were associated with photosynthesis. These results provide new information for the study of cassava resistance to PPD and lay a foundation for the further molecular breeding of storage-tolerant cassava varieties.

Cassava (Manihot esculenta Crantz) is used as a biomass energy material and an effective supplement for food and feed. Cinnamyl alcohol dehydrogenase (CAD) catalyzes the final step of lignin biosynthesis and is responsible for various stresses. However, systematic investigations of the CAD gene family in cassava have been poorly understood. In this study, a genome-wide survey and bioinformatics analysis of CAD gene family was performed, transcriptomics, qRT-PCR, gene silencing and stress of yeast cell were used for excavate and validate the candidate MeCADs gene. 36 MeCADs genes unevenly distributed across 12 chromosomes were identified. Through phylogenetic analyses alongside their Arabidopsis counterparts, these MeCADs were divided into four groups, each containing a similar structure and conserved motifs. Interestingly, transcriptome data analysis revealed that 32 MeCAD genes were involved in the postharvest physiological deterioration (PPD) process, whereas 27 MeCAD genes showed significant changes. Additionally, the relative quantitative analysis of 6 MeCAD genes demonstrated that they were sensitive to PPD, suggesting that they may be involved in the regulation of PPD. Silencing MeCAD13 and MeCAD28 further showed that lignin content significantly decreased in the leaves. The wound-stress tolerance of transgenic yeast cells was enhanced after transformation with MeCAD13 and MeCAD28. MeCAD13 and MeCAD28 may play positive roles in lignin biosynthesis and PPD response, respectively. These results provided a systematic functional analysis of MeCADs in cassava and paved a new way to genetically modify lignin biosynthesis and PPD tolerance.

The short postharvest life of cassava is mainly due to its rapid postharvest physiological deterioration (PPD) and cell oxidative damage, however, how to effectively control this remains elusive. In this study, South China 5 cassava slices were sprayed with water and methyl jasmonate (MeJA) to study the effects of MeJA on reactive oxygen species, antioxidant enzymes, quality, endogenous hormone levels, and melatonin biosynthesis genes. We found that exogenous MeJA could delay the deterioration rate for at least 36 h and alleviate cell oxidative damage through activation of superoxide dismutase, catalase, and peroxidase. Moreover, MeJA increased the concentrations of melatonin and gibberellin during PPD, which had a significant effect on regulating PPD. Notably, exogenous MeJA had a significant effect on maintaining cassava quality, as evidenced by increased ascorbic acid content and carotenoid content. Taken together, MeJA treatment is an effective and promising way to maintain a long postharvest life, alleviate cell oxidative damage, and regulate storage quality in cassava.

Massive economic losses and the decrease in quality of cassava are caused by postharvest physiological deterioration (PPD). However, an effective solution remains limited. In this study, the role of ethanol in the PPD of cassava was investigated and highlighted. Exogenous ethanol delayed PPD and reduced the accumulation of reactive oxygen species, while increased the underlying activities of superoxide dismutase, catalase, peroxidase, and 2,2’-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging. Moreover, exogenous ethanol increased the endogenous levels of ethylene and melatonin, all of which are negative regulators of PPD. Notably, this study found that exogenous ethanol reduced the degradation of starch, but enhanced ascorbic acid content and carotenoid content. In summary, these results revealed the novel role of ethanol in delaying PPD and improving the quality of cassava tubes without ethanol residue, suggesting an effective and promising way in cassava.