Storage Longevity Research Articles

Keratin-reinforced encapsulation of whole cells expressing glucose isomerase: Development of robust and reusable biocatalyst microbeads.

Glucose isomerase (GI) is crucial in high-fructose corn syrup production. This study introduces a novel approach to enhance GI stability and reusability through whole-cell encapsulation of Streptomyces olivochromogenes PTCC 1457 in hybrid microbeads, utilizing keratin as a multifunctional stabilizer and cross-linker. Optimal bead formation was achieved using 2 % alginate, 2-3 % CaCl2, and 2.5 % keratin at pH 7.0 and 37-40 °C. Keratin played a vital role in forming a robust and flexible matrix. Immobilization in keratin-alginate-biomass beads maintained GI activity (655 GIU·g-1) comparable to free enzyme (650 GIU·g-1), while silicate incorporation reduced activity to 234 GIU·g-1. The immobilized enzyme exhibited enhanced stability over a wider pH (6-9) and temperature (4-60 °C) range compared to the free enzyme. Importantly, the immobilized GI maintained 80 % of its initial activity after 20 reaction cycles. Thermogravimetric analysis, scanning electron microscopy, energy dispersive X-ray spectroscopy, and tensile testing confirmed the formation of hybrid beads with improved thermal and mechanical stability. This novel immobilization strategy, leveraging keratin's unique properties, offers a promising approach for enhancing GI stability, reusability, and storage longevity, potentially improving its industrial applicability in high-fructose corn syrup production.

Symmetric two-electodes pseudosupercapacitor from trichalcogenide MoS3-MoO3-poly-O-amino-benzenethiol nanocomposite

A novel nanocomposite, MoS3-MoO3/poly-O-amino-benzenethiol (MoS3-MoO3/POABT), has been synthesized in a one-pot process and demonstrates promising applications as a material for a two-electrode configuration supercapacitor. This nanocomposite exhibits remarkable morphological characteristics, featuring uniform particles with an average diameter of 80 nm and a porous structure. The advantageous morphology contributes to the enhanced performance of the fabricated pseudo supercapacitor. The evaluation of the charge/discharge behavior and cyclic voltammetry curves of the redox reaction of the MoS3-MoO3/POABT nanocomposite reveals its efficacy as a supercapacitor material. The specific capacitance (CS) achieved for this fabricated supercapacitor is noteworthy at 152 F/g. Furthermore, the energy density (E) peaks at 12.6 W h kg−1 when operating at a current density of 0.2 A/g. This high energy density demonstrates the supercapacitor’s ability to store significant energy for practical use efficiently. Importantly, its stability remains strong, with an impressive 98% retention after 250 cycles, and even after 1000 cycles, it only slightly decreases to 95%. This remarkable stability over extended cycling periods underscores the durability of the materials in the supercapacitor. Such reliable performance establishes the MoS3-MoO3/POABT nanocomposite as a dependable choice for supercapacitor applications, ensuring longevity and consistent performance in diverse energy storage needs.

Redox dynamics in seeds of Acer spp: unraveling adaptation strategies of different seed categories.

Seeds of woody plant species, such as those in the Acer genus like Norway maple (Acer platanoides L.) and sycamore (Acer pseudoplatanus L.), exhibit unique physiological traits and responses to environmental stress. Thioredoxins (Trxs) play a central role in the redox regulation of cells, interacting with other redox-active proteins such as peroxiredoxins (Prxs), and contributing to plant growth, development, and responses to biotic and abiotic stresses. However, there is limited understanding of potential variations in this system between seeds categorized as recalcitrant and orthodox, which could provide insights into adaptive strategies. Using proteomic analysis and DDA methods we investigated the Trx-h1 target proteins in seed axes. We complemented the results of the proteomic analysis with gene expression analysis of the Trx-h1, 1-Cys-Prx, and TrxR NTRA genes in the embryonic axes of maturing, mature, and stored seeds from two Acer species. The expression of Trx-h1 and TrxR NTRA throughout seed maturation in both species was low. The expression of 1-Cys-Prx remained relatively stable throughout seed maturation. In stored seeds, the expression levels were minimal, with slightly higher levels in sycamore seeds, which may confirm that recalcitrant seeds remain metabolically active during storage. A library of 289 proteins interacting with Trx-h1 was constructed, comprising 68 from Norway maple and 221 from sycamore, with distinct profiles in each seed category. Recalcitrant seed axes displayed a wide array of metabolic, stress response, and signaling proteins, suggesting sustained metabolic activity during storage and the need to address oxidative stress. Conversely, the orthodox seed axes presented a protein profile, reflecting efficient metabolic shutdown, which contributes to their extended viability. The results of the study provide new insights into seed viability and storage longevity mechanisms. They enhance the understanding of seed biology and lay the foundation for further evolutionary research on seeds of different categories.

Enhancing the Storage Longevity of Apples: The Potential of Bacillus subtilis and Streptomyces endus as Preventative Bioagents against Post-Harvest Gray Mold Disease, Caused by Botrytis cinerea.

Gray mold, caused by Botrytis cinerea Pers. Fr., is one of the most vital plant diseases, causing extensive pre- and post-harvest losses in apple fruits. In the current study, we isolated and identified two potential endophytic bioagents, Bacillus subtilis and Streptomyces endus. Both bioagents exhibited a potent fungistatic effect against B. cinerea under both in vitro and in planta conditions. Moreover, two experiments were carried out; (i) the first experiment was conducted at room temperature after artificial inoculation with B. cinerea to monitor the progression of the infection and the corresponding biochemical responses of the apples. Our in vivo findings showed that the treated B. cinerea-infected apple fruits with the cell-free bacterial filtrate of B. subtilis and S. endus (dipping or wrapping) significantly reduced the rotten area of the treated apple at room temperature. Additionally, B. subtilis and S. endus enhanced the enzymatic (POX and PPO) and non-enzymatic (phenolics and flavonoids) antioxidant defense machinery in treated apples. (ii) The second experiment focused on the preventive effects of both bioagents over a 90-day storage period at 1 °C of healthy apples (no artificial inoculation). The application of both bacterial filtrates prolonged the storage period, reduced the relative weight loss, and maintained high-quality parameters including titratable acidity, firmness, and total soluble solids of apple fruits under cold storage at 1 °C. The Kaplan-Meier analysis of rotten apples over 90 days during cold storage showed that the treated apples lasted longer than the non-treated apples. Moreover, the lifespan of apple fruits dipped in the culture filtrate of B. subtilis, or a fungicide, was increased, with no significant differences, compared with the non-treated apples. The current results showed the possibility of using both bioagents as a safe and eco-friendly alternative to chemical fungicides to control gray mold disease in apples.

Marigold Seed Pelleting with Plant Nutrients on Germination, Growth, Storage and Flower Yields

Background: Seed pelleting, a method involving seed coatings to enlarge seed size, is advantageous for marigold seeds because it improves water utilization efficiency during germination. Furthermore, the incorporation of vital plant nutrients into seeds fosters germination and growth, facilitating accelerated growth and increased yield in marigold plants. Methods: Marigold seeds were pelleted with NH4NO3 at rates of 0.048, 0.096 and 0.192 g, NaH2PO4.H2O at rates of 0.064, 0.128 and 0.256 g and KCl at rates of 0.013, 0.026 and 0.052 g. Growth was determined after incubation in 4 × 6 inch bags for 56 days. Storage longevity was determined after incubation in aluminum foil bags under controlled (15°C, 50% RH) and ambient conditions (27±2°C, 70% RH) for 6 months. Result: Seeds pelleted with NH4NO3, NaH2PO4.H2O and KCl demonstrated superior germination rates and germination speed. NaH2PO4.H2O pelleting led to increased shoot dry weight. The use of 0.256 g NaH2PO4.H2O resulted in the highest germination rate over 6 months. Pelleting with all three nutrients resulted in higher plants, particularly 0.256 g NaH2PO4.H2O, which led to more flowers per plant. Therefore, pelleting seeds with 0.256 g NaH2PO4.H2O is recommended to optimize the quality of marigold seeds.

Improving flow dynamics and storage longevity of a low-cost phosphorescent fingerprint powder.

An inexpensive, commercially available doped strontium aluminate phosphor with long-lived afterglow was prepared as a luminescent fingerprint dusting powder suited for challenging, highly patterned substrates; however, prolonged exposure to humidity was found to reduce that powder's affinity for fingermarks. Here, an enhanced preparation for synthesizing that fingerprint dusting powder is presented that prevents powder aggregation and loss of function upon exposure to humid environments. This was achieved by introducing a flow regulator during synthesis: hydrophobic silica SIPERNAT® D10 or SIPERNAT® D17. Increasing the hydrophobicity of the powder prevents aggregation by inhibiting the uptake of water, thereby improving the material's flow dynamics and transfer behavior from brush to fingermark. The angle of repose and flow characteristics made by the modified powders were quantified, with excellent affinity for fingermarks observed, even after being stored under 85% (±5%) humidity for 4 weeks. A preliminary comparison of the performance of the modified hydrophobic powders relative to the unmodified precursor revealed that more of the SIPERNAT® treated powder typically adhered to fingermarks while simultaneously imparting less background development. In addition, fewer clumps of particulate were observed in the developed fingermarks after addition of a hydrophobic flow regulator. This technical report outlines the updated method for synthesizing the fingerprint powder, with summarized flow performance results, and a demonstration of the modified powder's affinity for simulated fingermark evidence.

Biochemical characterization of immobilized recombinant subtilisin and synthesis and functional characterization of recombinant subtilisin capped silver and zinc oxide nanoparticles

This pioneering research explores the transformative potential of recombinant subtilisin, emphasizing its strategic immobilization and nanoparticle synthesis to elevate both stability and therapeutic efficacy. Achieving an impressive 95.25 % immobilization yield with 3 % alginate composed of sodium along with 0.2 M CaCl2 indicates heightened pH levels and thermal resistance, with optimal action around pH 10 as well as 80 °C temperature. Notably, the Ca-alginate-immobilized subtilisin exhibits exceptional storage longevity and recyclability, affirming its practical viability. Comprehensive analyses of the recombinant subtilisin under diverse conditions underscore its adaptability, reflected in kinetic enhancements with increased Vmax (10.7 ± 15 × 103 U/mg) and decreased Km (0.19 ± 0.3 mM) values post-immobilization using N-Suc-F-A-A-F-pNA. UV–visible spectroscopy confirms the successful capping of nanoparticles made of Ag and ZnO by recombinant subtilisin, imparting profound antibacterial efficacy against diverse organisms and compelling antioxidant properties. Cytotoxicity was detected against the MCF-7 breast cancer line of cells, exhibiting IC50 concentrations at 8.87 as well as 14.52 µg/mL of AgNP as well as ZnONP, correspondingly, indicating promising anticancer potential. Rigorous characterization, including FTIR, SEM-EDS, TGA and AFM robustly validate the properties of the capped nanoparticles. Beyond therapeutic implications, the investigation explores industrial applications, revealing the versatility of recombinant subtilisin in dehairing, blood clot dissolution, biosurfactant activity, and blood stain removal. In summary, this research unfolds the exceptional promise of recombinant subtilisin and its nanoparticles, presenting compelling opportunities for diverse therapeutic applications in medicine. These findings contribute substantively to biotechnology and healthcare and stimulate avenues for further innovation and exploration.

Water barrier coating of chitosan/poly (vinyl alcohol)/trans-cinnamaldehyde regulated postharvest quality and reactive oxygen species metabolism of ‘Frutica’ tomato (Solanum lycopersicum L.)

The ‘Frutica’ tomato (Solanum lycopersicum L.), a nutritious “king of fruit,” faces restricted marketability in storage. This study focused on enhancing storage longevity and regulating reactive oxygen species (ROS) metabolism in these tomatoes using chitosan (CS), polyvinyl alcohol (PVA), and trans-cinnamaldehyde (CIN) water barrier coatings and investigated their underlying mechanisms. Tomatoes coated with four different coating formulations and uncoated fruit were stored for 30 d at 8 °C and 75% relative humidity. The bioactive films were evaluated for microstructure (scanning electron microscopy; atomic force microscopy), water barrier, and antifungal properties and tested every 5 d for physical and chemical indices, quality, and ROS of the postharvest fruit. The results showed that the addition of CIN increased the structural density, water barrier properties, and Botrytis cinerea resistance of the coatings. The CIN-containing coating significantly improved water loss, firmness, titratable acid (TA) value, color, and appearance; decreased lipid peroxidation; and modulated the ROS scavenging system compared with other treatment groups. Principal component analysis and correlation revealed that the CIN-coated material, characterized by water-barrier properties, contributed positively to the preservation of tomatoes during refrigeration. Water barrier coating facilitates the enzymatic ROS scavenging system in tomatoes, thereby extending their senescence.

Gendered trait prioritization and motivations for crop varietal choice among smallholder farmers: The case of sweetpotato in Uganda

To improve productivity, several improved high-yielding sweetpotato varieties have been developed and released by breeders. However, most farmers still grow low-yielding landraces known also as farmers’ varieties. Farmers choose varieties to grow based on their preference for the attributes (traits) embodied in those varieties. Past studies have examined drivers of trait preference using neoclassical economic theory. This study departs from previous ones by applying principles from economic psychology to assess preference for, and prioritization, of sweetpotato traits among male and female sweetpotato farmers. Data used was data collected using focus group discussions and laddering, an in-depth personal interview process, and analysed using descriptive and means-end chain analyses. The study identifies mental constructs associated with farmers’ trait preference and prioritization, namely: the characteristics farmers mentally associate with the prioritized traits, the benefits those traits confer, and the life goals (i.e. values) they enable farmers to attain. Focus group discussions revealed that, among agronomic traits, high root yield is the most preferred/prioritized trait across gender categories and was followed by stress tolerance and underground root storage longevity. The most preferred quality traits across gender groups are root size and mealiness. Women, however, prioritized early maturity over men. The means-end-chain analysis identified several mental constructs farmers mentally associated with trait prioritization. They are increased sales, more income, food security, savings, and investment. These benefits are linked to various life goals (values) farmers aspire for namely, respect, security, achievement, and happiness. These findings imply that farmers’ choice of sweetpotato varieties to grow is driven by the agronomic and quality traits the varieties embody. The findings further imply that psychosocial factors underpin trait preference and prioritization by farmers.

Effect of space electric field on the shelf-life extension of plum fruit (GuoFeng17)

This study investigated the efficacy of DENBA+ as a non-contact cold chain preservation method on the storage longevity and quality of plums. Experiments were conducted at a cold storage temperature of 0 ± 0.5 °C over 49 days across varying electric field intensities (0, high, and low DENBA+). The findings revealed that the low DENBA+ notably reduced weight loss, maintained firmness, and inhibited enzymatic browning by curbing POD and PPO activities and reducing total phenol content. In comparison to the control, plums under low DENBA+ treatment displayed higher concentrations of total sugars and soluble solids. Additionally, this treatment effectively delayed increases in MDA content and membrane permeability. Contrastingly, the high DENBA + treatment minimally influenced enzymatic activities but rather intensified MDA levels and membrane permeability. The data suggest that the low DENBA+(with an electric field intensity between 500 and 800 V m−1) emerges as a promising preservation approach for plum.

Evaluation of the storage longevity, postharvest quality, and sugar metabolism-related gene expression in two lines (N1 and N3) of Chinese cabbage during long-term storage

The quality and taste of ‘Beijing New 3′ (N3) and Beijing New 1′ (N1) Chinese cabbage was assessed using physiological indicators monitored during storage and by transcriptome profiling conducted at 0, 25, and 100 d of storage. Results indicated that N3 had better storage longevity and postharvest quality, relative to N1. Electrolyte leakage values in N3 increased at a slower rate than they did in N1 cabbage during the latter stages of storage (125 days), while ethylene levels and respiratory rates were also lower in N3 cabbage than in N1 cabbage during the entire period of storage. The N3 variety had a higher sugar content (mainly glucose and fructose) during storage than the N1 variety. The expression level of genes involved in sugar metabolism, such as hexokinase (HK), sucrose synthase (SUS), phosphofructokinase (PFK), fructose bisphosphate aldolase (FBA), PCKA (Phosphoenolpyruvate carboxykinase), ALDO (aldose), GAPDH (glyceraldehyde phosphate dehydrogenase), and ENO (Enolase) were higher in N3 than in N1, while the expression level of GPI (Glycosylphosphatidylinositol) and PGM (Phosphoglucomutase) was lower. These results provide valuable information on the quality and taste of Chinese cabbage, especially in relation to sugar metabolism, and indicated that N3 had better postharvest storage properties than N1.

IMPORTANCE OF SEED QUALITY FOR THE FORESTRY SECTOR

Plant production is essential for the maintenance of human activity on Earth, and as seeds are the main tool for plant propagation, obtaining high-quality seeds is essential for successful planting. Forest species are applied in diff erent areas, such as timber, the pharmaceutical industry, landscaping projects, and degraded area recovery. The search for seedlings of forest species has increased due to the intense exploitation of ecosystems and the need to recover degraded areas. Therefore, it is necessary to use high-quality seeds that are composed of a complex set of attributes, including genetic, physical, physiological, and sanitary factors that directly infl uence the performance of seeds in the fi eld and their longevity in storage. Forest seeds have peculiarities, such as variable size and shape, nonuniform water content and germination speed, as well as diff erent drying and storage capacities. In addition, they have high genetic variability, which implies diffi culties in their management, such as the presence of dormancy, which can aff ect seed quality and seedling production. Seed germination and vigor are critical factors for the quality of forest seeds, but many species have not yet identifi ed their germination requirements. The lack of information about the peculiarities of each forest species and the high genetic variability among them makes it diffi cult to standardize methods for analyzing the physiological quality of seeds, in addition to becoming an obstacle to their use in reforestation projects, since the lack of diversity in the use of native species is a concern, as it reduces variety and endangers biodiversity

The potential impacts of climate change on ex situ conservation options for recalcitrant-seeded species

Recalcitrant seeds are characterized by desiccation and freezing sensitivity, and short storage longevity. These physiological attributes obviate their ex situ conservation in conventional seed banks, where seeds are stored dry at sub-zero temperatures (typically, 15% relative humidity and –20°C) for extended periods of time. Propagation of plants for field collections (e.g., botanical gardens, nurseries, and arboretums) is a valuable ex situ conservation option. However, these collections are relatively costly, require high maintenance, preserve limited genetic diversity and/or are directly exposed to biotic (e.g., pests) and abiotic (e.g., climatic) threats. Therefore, recalcitrant-seeded (RS) species are dependent on cryopreservation for their safe and long-term ex situ conservation. Different explant sources such as whole seeds, zygotic embryos, dormant buds, shoot tips, and pollen, can be used for plant propagation of RS species in field collections as well as for their cryopreservation. The success of the propagation or the cryopreservation of these explants often depends on their developmental status, vigor, and/or tolerance to desiccation and chilling/freezing. These attributes are modulated by the environment where the donor plant grows and we hypothesize that climate change, by affecting these biological attributes, would impact the success of explant propagation and cryopreservation. To support this hypothesis, we have reviewed how temperature changes and drought, the two main climate change scenarios, affect the main biological attributes that are directly involved in the success of ex situ conservation of tropical and temperate RS species. In general, increases in temperature and drought will negatively affect plant development in field collections and the quality of the explants used in cryopreservation. Consequently, field collections of RS species may need to be moved to more suitable places (e.g., higher latitudes/altitudes). Additionally, we may find a reduction in the success of cryopreservation of RS species germplasm directly harvested from field collections. However, we cannot always generalize these effects for all species since they often depend on the origin of the species (e.g., tropical and temperate species tend to respond to climate change differently), the genotype, the adaptive genetic potential of each population, and the severity of the environmental change. On the other hand, the increase in temperatures and water stress in donor plants at high-latitude areas and also some tropical environments may favor the production of seeds and seedlings better adapted to drying, and hence, increase the success of plant propagation and zygotic embryo cryopreservation.

Physiological disorders, textural property, and cell wall metabolism of ‘Gem’ pears (Pyrus communis L.) affected by oxygen regimes and harvest maturity under controlled atmosphere storage

The primary purpose of this study was to develop optimal controlled atmosphere (CA) strategies for the pear industry to utilize ‘Gem’ pears. The influences of two O2 regimes (1.0% O2 and 2.2% O2 [commercial practice concentration] with ∼0.05% CO2) on decay, physiological disorders (i.e. internal breakdown, superficial scald, and black speck), storage and eating quality attributes, cell wall components, and cell wall-modifying enzymes were evaluated at two harvest maturities (H1; 48.01 N; H2; 42.19 N) of ‘Gem’ pears. Earlier harvested pears (H1) stored under regular-air (RA) conditions had lower rates of superficial scald and internal breakdown relative to later harvested pears (H2), especially in extended storage (8–10 months). However, storage and eating quality for air-stored H1 and H2 fruit deteriorated after 6 months. CA regimes extended ‘Gem’ storage longevity from 8 to 10 months, with 1.0% O2 resulting in lower incidences of superficial scald and internal breakdown disorders and higher peel chlorophyll content and titratable acidity by delaying the peak of ethylene production rate (EPR) compared to 2.2% O2. Notably, the rates of black speck in H1 and H2 fruit were controlled at below 5% in both O2 regimes. Furthermore, 1.0 and 2.2% O2 stored H1 and H2 pears ripened and developed a melting texture with full flavor and juiciness during 6–8 months of storage. Additionally, the water-soluble (WSP), cyclohexanetrans-1,2-diaminetetra-soluble (CSP), and Na2CO3-soluble polyuronides (SSP) combined with pectin methylesterase (PME), α-arabinofuranosidase (α-ARF), and β-galactosidase (β-GAL) contributed to fruit softening and desirable eating quality in ‘Gem’ pears. In conclusion, 2.2% O2 with ∼0.05% CO2 improved the fruit quality of ‘Gem’ pears harvested at 48.01 N, while the quality of fruit harvested at 42.19 N or below could be improved by the application of 1.0% O2.

Seed invigoration using ultrafine bubble water to increase the vigor of true shallot seed (Allium ascalonicum L.)

True shallot seeds are preferable to tubers as planting materials because of their advantages in storage longevity, lower management cost, and lower seed-borne disease risk. However, environmentally limited production and seed deterioration in uncontrolled storage have limited its application. Pre-sowing hydration invigoration accelerates and synchronizes the germination of deteriorated seeds. Ultra-fine bubble water (UFBW) contains reactive oxygen species, which can advance the pre-germinative metabolism of the seed. This study examined true shallot seed invigoration using UFBW. The experiment was conducted in a two-factor of randomized complete block design. The first factor was initial seed vigor based on the vigor index with six levels, i.e., 24, 15, 13, 12, 10, and 9%. The second factor was the invigoration treatment of UFBW (8 and 23 ppm dissolved oxygen concentrations) with two durations (24 and 48 h), 50 ppm GA3, and 3% KNO3 (24 h). UFBW with 23 ppm invigoration for 48 h improved seed vigor based on all vigor parameters. The GA3 50 ppm treatment is the most effective in increasing seed vigor.
 Keywords: dissolved oxygen; pre-sowing hydration; reactive oxygen species; seed viability; seed vigor

Are orthodox Australian rainforest seeds short-lived in storage?

Context Fifty per cent of Australian rainforest species produce orthodox seeds, but little is known about their longevity in storage. Aims To (1) estimate the longevity of seeds of 33 rainforest species using artificial aging; (2) assess the influence of habit, habitat range (restricted to rainforest or more broadly distributed), seed characteristics (endospermy, dry weight), and collection environment (e.g. precipitation, elevation and average temperature) on longevity; (3) compare longevity of rainforest seeds to previously assessed species from non-rainforest habitats; (4) compare longevity in artificial aging to real-time longevity in storage. Methods Seeds were aged at 60% relative humidity and 45°C, and tested at pre-determined intervals until germination was reduced to zero. The time taken for germination to decline to 50% (p50AA) was calculated by probit analysis. Ordinary least-squares regression was used to model p50AA for rainforest and non-rainforest species against predictor variables. Values for p50AA were then compared with the actual longevity in storage at −20°C (p50RT) using Pearson’s correlation. Key results Species restricted to rainforest exhibited a significantly lower p50AA than species with a wider distribution or those restricted to non-rainforest habitats. Collection elevation had a significant negative influence on p50AA. In all, 14 of 33 species showed a significant decline in viability after ≤12 years in storage. Values of p50AA were not correlated with p50RT. Conclusions Rainforests contain a high proportion of potentially, and actually, short-lived species; however, p50AA is not a good predictor of their real-time longevity. Implications Rainforest species should be managed as short-lived, with viability checked at least every 5 years, until real-time longevity data indicate otherwise.

Can alpine plant species "bank" on conservation?: Using artificial aging to understand seed longevity.

PremiseTo conserve native plants, many institutions are turning toward ex‐situ conservation methods, such as storage in seed banks; however, not all seeds are able to survive in seed bank conditions, or may not in the long term. Experimental aging has shown that alpine species lose viability more quickly than low‐elevation species. Furthermore, the germination requirements for rare species are largely unknown, but are a necessary first step in understanding storage behavior and viability decline.MethodsFive alpine species were subjected to germination and accelerated aging experiments to understand their longevity in storage. For the accelerated aging experiment, the seeds were rehydrated in a dark incubator and subsequently placed in a drying oven. Following the aging process, the seeds were placed into previously determined germination conditions.ResultsAll species had p 50 values of <13.7 days, which is the threshold to consider a species short lived. These results suggest that we cannot haphazardly store seeds and assume that all species will survive for decades.DiscussionAccelerated aging experiments are not a perfect measure of seed longevity, and true longevity needs to be empirically determined. However, this experimental method allows us to predict which species may be short lived and whether alternative ex‐situ conservation methods might be needed beyond conventional seed banking.

Novel carboxymethyl chitosan/N-acetylneuraminic acid hydrogel for the protection of Pediococcus pentosaceus

In this study, carboxymethyl chitosan (CMCS) and N-acetylneuraminic acid (NeuAc) were used to develop C-NeuAc hydrogels to encapsulate Pediococcus pentosaceus QK-1. The mechanical properties, thermal stability, in vitro degradation, and pH sensitivity of the hydrogel were evaluated. The C-NeuAc concentration required for optimal hydrogel performance was 3% (w/v). Hydrogel swelling behaviour was effectively assessed by Fickian diffusion and Schott’s second-order kinetic models. The hydrogel demonstrated excellent biocompatibility and low in vitro cytotoxicity. An in vitro assay revealed that the viability of Pediococcus pentosaceus QK-1 in C-NeuAc had decreased by only 1.41 log (CFU/ mL) after exposure to simulated acidic gastric fluid. Moreover, the survival rate of the encapsulated and free Pediococcus pentosaceus QK-1 cells were 80.1% and virtually zero, respectively, after passage through the gastrointestinal tract. It was empirically determined that low temperature and freeze-drying were the ideal condition and method to ensure storage longevity of the hydrogel-encapsulated probiotic. Hence, C-NeuAc hydrogel is highly desirable as a food-grade probiotic delivery vehicle.

The radicle emergence test and storage longevity of cucurbit rootstock seed lots

A study was carried out to test whether a single count of radicle emergence (RE test) would correlate with the storage potential of seed lots of cucurbit (C. maxima × C. moschata) rootstock cultivars. The RE test was performed by counting radicle emergence percentage between 26 and 100 hours of germination. Seed longevity was determined by storage at 75% relative humidity at 35°C over 100 days, with seed survival curves constructed based on normal germination percentages. Ki (estimated initial viability in probits), σ (standard deviation of the normal distribution of seed death in time) and p50 (time for viability to fall to 50%) were determined through probit analysis. Correlation analysis showed that RE counts particularly between 30 and 34 hours were highly (P &lt; 0.01) correlated with normal germination percentage, Ki and p50. It can be concluded that RE tests can be used as an indicator of subsequent seed lot longevity in cucurbit rootstock seed cultivars.

A polygalacturonase gene PG031 regulates seed coat permeability with a pleiotropic effect on seed weight in soybean.

A QTL gene PG031 regulates the seed coat permeability and seed weight. The critical SNP that can explain the variation of permeability in soybean population can be used for seed improvement. Seed coat permeability is a critical trait for soybean and is tightly associated with seed storage longevity, germination, soy-food processing, and other commercially important traits. However, the molecular mechanism of such an important trait in soybean is largely unclear. In the present study, we uncovered a polygalacturonase (PG) gene, PG031, which controls seed coat permeability in soybean. PG031 exhibited tissue expression specificity in flowers while it was strongly induced in the seed coat and radical upon imbibition. Subcellular localization localized PG031 to the cell wall, suggesting its role specific to the cell wall of the seed coat. Natural variation analysis reveals three haplotypes (PG031289H, PG031289Y, and PG031Hap3) and the single nucleotide polymorphism (SNP) variation for H289Y may explain the variation in permeability in cultivated soybean population. Overexpression of impermeable allele PG031289H significantly reduced the seed coat permeability and 100-seed weight in transgenic seeds through decreasing intracellular spaces of the osteosclereid layer and parenchyma of the seed coat to decline water accessing the seed. PG031 was also located within a quantitative trait locus (QTL) explaining ~ 15% of total phenotypic variation in permeability, nominating it the QTL gene controlling permeability. PG031289Y allele associated with high permeability and high seed weight is experiencing ongoing artificial selection. The results provide insight into the genetic mechanism of seed coat permeability and indicate its potential for the improvement of permeability-associated seed traits in soybean.