Application of methyl jasmonate to control chilling tolerance of postharvest fruit and vegetables: a meta-analysis and eliciting metabolism review.

Chilling injury is one of the most significant limitations for low temperature storage of postharvest fruits and vegetables, causing quality deterioration and economic loss. Increasing studies indicated that methyl jasmonate (MeJA) is critical in regulating the postharvest fruit and vegetables chilling tolerance. Based on a meta-analysis, the review analyzed the action of exogenous MeJA application on the chilling index in postharvest fruit and vegetables and summarized MeJA's mechanisms for controlling postharvest chilling injury. The meta-analysis found that MeJA treatment remarkably inhibited postharvest fruit and vegetable chilling injury. Moreover, we concluded the following function mechanism of MeJA on postharvest fruit and vegetable chilling tolerance: (1) Enhancing membrane integrity and energy supply, (2) Increasing antioxidant activity, (3) Enhancing arginine pathway, (4) Enhancing sugar metabolism, (5) Regulating phenolic metabolism, (6) Activating CBF pathway, (7) Regulating HSP accumulation and expression, and (8) Crosstalk with phytohormone. Finally, we summarized the regulatory mechanisms of MeJA on postharvest fruit and vegetable biological processes at the transcriptional and post-translational levels.

Emerging roles and mechanisms of lncRNAs in fruit and vegetables.

With the development of genome sequencing technologies, many long non-coding RNAs (lncRNAs) have been identified in fruit and vegetables. lncRNAs are primarily transcribed and spliced by RNA polymerase II (Pol II) or plant-specific Pol IV/V, and exhibit limited evolutionary conservation. lncRNAs intricately regulate various aspects of fruit and vegetables, including pigment accumulation, reproductive tissue development, fruit ripening, and responses to biotic and abiotic stresses, through diverse mechanisms such as gene expression modulation, interaction with hormones and transcription factors, microRNA regulation, and involvement in alternative splicing. This review presents a comprehensive overview of lncRNA classification, basic characteristics, and, most importantly, recent advances in understanding their functions and regulatory mechanisms.

Antifungal potential of lipopeptides produced by the Bacillus siamensis Sh420 strain against Fusarium graminearum.

Biological control is a more sustainable and environmentally friendly alternative to chemical fungicides for controlling Fusarium spp. infestations. In this work, Bacillus siamensis Sh420 isolated from wheat rhizosphere showed a high antifungal activity against Fusarium graminearum as a secure substitute for fungicides. Sh420 was identified as B. siamensis using phenotypic evaluation and 16S rDNA gene sequence analysis. An in vitro antagonistic study showed that Sh420's lipopeptide (LP) extract exhibited strong antifungal properties and effectively combated F. graminearum. Meanwhile, lipopeptides have the ability to decrease ergosterol content, which has an impact on the overall structure and stability of the plasma membrane. The PCR-based screening revealed the presence of antifungal LP biosynthetic genes in this strain's genomic DNA. In the crude LP extract of Sh420, we were able to discover several LPs such as bacillomycin, iturins, fengycin, and surfactins using ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry. Microscopic investigations (fluorescent/transmission electron microscopy) revealed deformities and alterations in the morphology of the phytopathogen upon interaction with LPs. Sh420 LPs have been shown in grape tests to be effective against F. graminearum infection and to stimulate antioxidant activity in fruits by avoiding rust and gray lesions. The overall findings of this study highlight the potential of Sh420 lipopeptides as an effective biological control agent against F. graminearum infestations.IMPORTANCEThis study addresses the potential of lipopeptide (LP) extracts obtained from the strain identified as Bacillus siamensis Sh420. This Sh420 isolate acts as a crucial player in providing a sustainable and environmentally friendly alternative to chemical fungicides for suppressing Fusarium graminearum phytopathogen. Moreover, these LPs can reduce ergosterol content in the phytopathogen influencing the overall structure and stability of its plasma membrane. PCR screening provided confirmation regarding the existence of genes responsible for biosynthesizing antifungal LPs in the genomic DNA of Sh420. Several antibiotic lipopeptide compounds were identified from this bacterial crude extract using ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry. Microscopic investigations revealed deformities and alterations in the morphology of F. graminearum upon interaction with LPs. Furthermore, studies on fruit demonstrated the efficacy of Sh420 LPs in mitigating F. graminearum infection and stimulating antioxidant activity in fruits, preventing rust and gray lesions.

Interaction of methionine sulfoxide reductase B5 with SlMYC2 stimulates the transcription of MeJA-mediated autophagy-related genes in tomato fruit.

Methyl jasmonate (MeJA) has been shown to induce autophagy in various plant stress responses and metabolic pathways. MYC2 is involved in MeJA-mediated postharvest fruit biological metabolism, but it is unclear how it affects MeJA-induced fruit autophagy. In this study, we noticed that silencing SlMYC2 significantly reduced the increase in autophagy-related genes (SlATGs) expression induced by MeJA. SlMYC2 could also bind to the promoters of several SlATGs, including SlATG13a, SlATG13b, SlATG18a, and SlATG18h, and activate their transcript levels. Moreover, SlMsrB5, a methionine sulfoxide reductase, could interact with SlMYC2. Methionine oxidation in SlMYC2 and mimicking sulfoxidation in SlMYC2 by mutation of methionine-542 to glutamine reduced the DNA-binding ability and transcriptional activity of SlMYC2, respectively. SlMsrB5 partially repaired oxidized SlMYC2 and restored its DNA-binding ability. On the other hand, silencing SlMsrB5 inhibited the transcript levels of SlMYC2-targeted genes (SlATG13a, SlATG13b, SlATG18a, and SlATG18h). Similarly, dual-luciferase reporter (DLR) analysis revealed that SlMsrB5-SlMYC2 interaction significantly increased the ability of SlMYC2-mediated transcriptional activation of SlATG13a, SlATG13b, SlATG18a, and SlATG18h. These findings demonstrate that SlMsrB5-mediated cyclic oxidation/reduction of methionine in SlMYC2 influences SlATGs expression. Collectively, these findings reveal the mechanism of SlMYC2 in SlATGs transcriptional regulation, providing insight into the mechanism of MeJA-mediated postharvest fruit quality regulation.

Enhancing crop resilience by harnessing the synergistic effects of biostimulants against abiotic stress.

Plants experience constant exposed to diverse abiotic stresses throughout their growth and development stages. Given the burgeoning world population, abiotic stresses pose significant challenges to food and nutritional security. These stresses are complex and influenced by both genetic networks and environmental factors, often resulting in significant crop losses, which can reach as high as fifty percent. To mitigate the effects of abiotic stresses on crops, various strategies rooted in crop improvement and genomics are being explored. In particular, the utilization of biostimulants, including bio-based compounds derived from plants and beneficial microbes, has garnered considerable attention. Biostimulants offer the potential to reduce reliance on artificial chemical agents while enhancing nutritional efficiency and promoting plant growth under abiotic stress condition. Commonly used biostimulants, which are friendly to ecology and human health, encompass inorganic substances (e.g., zinc oxide and silicon) and natural substances (e.g., seaweed extracts, humic substances, chitosan, exudates, and microbes). Notably, prioritizing environmentally friendly biostimulants is crucial to prevent issues such as soil degradation, air and water pollution. In recent years, several studies have explored the biological role of biostimulants in plant production, focusing particularly on their mechanisms of effectiveness in horticulture. In this context, we conducted a comprehensive review of the existing scientific literature to analyze the current status and future research directions concerning the use of various biostimulants, such as plant-based zinc oxide, silicon, selenium and aminobutyric acid, seaweed extracts, humic acids, and chitosan for enhancing abiotic stress tolerance in crop plants. Furthermore, we correlated the molecular modifications induced by these biostimulants with different physiological pathways and assessed their impact on plant performance in response to abiotic stresses, which can provide valuable insights.

Ultrasound based modification and structural-functional analysis of corn and cassava starch.

In this study, the starch molecules were modified with ultrasonication at two different time intervals by using starch molecules from corn and cassava. This research aimed to examine the effect of the high power ultrasound of 40 kHz voltage and frequency with short time duration on structural and physical properties of corn and cassava starch. Morphology of ultrasonically treated starch granules was observed by scanning electron microscopy (SEM), FTIR, differential scanning calorimetry (DSC), and X-ray diffraction (XRD) and compared with untreated samples. After the ultrasound treatment groove and notch appeared on the surface of the starch granules. The results showed that gelatinization temperature did not change with ultrasound treatments, but enthalpy value decreased from 13.15 ± 0.25 J/g to 11.5 ± 0.29 J/g and 12.65 ± 0.32 J/g to 10.32 ± 0.26 J/g for sonicated corn and cassava starches, respectively. The XRD results revealed a slight decreased in the crystallinity degree (CD) of sonicated corn (25.3,25.1) and cassava starch (21.0,21.4) as compared to native corn (25.6%) and cassava starch (22.2%). This study suggests that non-thermal processing techniques have the potential to modify the starch from different sources and their applications due to starch's versatility, low cost, and comfort of use after processing with altered physicochemical properties.

1-Methylcyclopropene treatment controls ethanol accumulation associated with regulation of mitochondrial energy metabolism in kiwifruit (Actinidia deliciosa) cv. "Bruno" during storage at room temperature.

In this paper, the effects of 1-methylcyclopropene (1-MCP) treatment on the ethanol accumulation and mitochondrial energy metabolism in kiwifruit (Actinidia deliciosa) cv. "Bruno" were investigated during storage at room temperature (24 ± 1°C). The results showed that 1-MCP treatment significantly reduced the ethanol accumulation, maintained higher levels of adenosine triphosphate (ATP) content and energy charge (EC), enhanced enzymes activities involved in mitochondrial energy metabolism, such as succinic dehydrogenase, cytochrome C oxidase, H+ -adenosine triphosphatase (H+ -ATPase), and Ca2+ -adenosine triphosphatase (Ca2+ -ATPase), and regulated the NADH/NAD+ ratio, and pyruvate to tricarboxylic acid cycle (TCA) by suppressing the glutamate-pyruvate transaminase and promoting the pyruvate dehydrogenase activity, and decarboxylation of citric acid in harvested kiwifruit. These shifts in mitochondrial energy metabolism and oxidative phosphorylation correlated the higher ATP yield and an elevated EC with lower ethanol accumulation (13.71% of those in the control fruit) under 1-MCP treatment, and reduced the susceptibility of ethanol related off-flavor disorder in kiwifruit during storage. PRACTICAL APPLICATIONS: A kiwifruit (Actinidia deliciosa) cv. "Bruno," a major cultivated kiwifruit in China, is prone to accumulate ethanol sharply after respiratory climacteric during storage. Ethanol has been accounted as a vital aroma volatile metabolite in various fruits. However, over accumulation of ethanol often leads to the development of alcohol off-flavor disorder, particularly in typical climacteric fruit such as kiwifruit. This work was aimed to maintain the flavor quality of kiwifruit cv. "Bruno" via improving the mitochondrial energy metabolism and functional TCA cycle, and limiting the ethanol accumulation under 1-MCP treatment. Thus, 1-MCP treatment could be beneficial to prevent the occurrence of alcohol off-flavor disorder along with sustainment of the flavor quality of kiwifruit cv. "Bruno" during storage at room temperature.

Bioavailability, rheology, and sensory evaluation of mayonnaise fortified with vitamin D encapsulated in protein-based carriers.

Vitamin D lost its functionality during processing and storage, thus, encapsulation with proteins is desirable to preserve bioactivity. The aim of the current study was to develop encapsulated vitamin D fortified mayonnaise (VDFM) using whey protein isolates (WPI) and soy protein isolates (SPI) as encapsulating materials in three different formulations, that is, 10% WPI, 10% SPI, and 5/5% WPI/SPI. Increased shear stress decreased the apparent viscosity along with significant effects on the loss modulus of VDFM. WPI encapsulates showed better results as compared to SPI. WPI based VDFM (M1 ) depicted the best results in terms of size and dispersion uniformity of oil droplets. Hue angle and total change differed significantly among treatments. The highest value for overall acceptability was acquired by M3 (5:5%WPI:SPI-encapsulates) thus proceed for in vivo trials. Serum vitamin D level was significantly higher in the encapsulated VDFM rat group (58.14 ± 6.29 nmol/L) than the control (37.80 ± 4.98 nmol/L). Conclusively, WPI and SPI encapsulates have the potential to improve the stability and bioavailability of vitamin D.

L-ascorbic acid metabolism in an ascorbate-rich kiwifruit (Actinidia. Eriantha Benth.) cv. 'White' during postharvest.

Kiwifruit (Actinidia eriantha Benth.) 'White', a novel cultivar with higher L-ascorbic acid (AsA) level, is registered in China. Changes in AsA, related metabolites, enzymatic activity, and gene expression associated with AsA biosynthesis and recycling process were investigated in this paper. The results indicated that AsA biosynthesis through L-galactose pathway supplemented by D-galacturonic acid pathway and AsA recycling collectively contributed to accumulating and remaining higher AsA level in kiwifruit cv. 'White' during postharvest. Moreover, L-galactose dehydrogenase (GalDH) activity and relative expressions of the genes encoding GDP-D-mannose pyrophosphorylase (GMP), L-galactose-1-P phosphatase (GPP), GDP-L-galactose phosphorylase (GGP), GalDH and D-galacturonate reductase (GalUR) were important for regulation of AsA biosynthesis, and the activity and expression of dehydroascorbate reductase (DHAR) were primarily responsible for regulation of AsA recycling in kiwifruit 'White' during postharvest.