Lignin Levels Research Articles

Analisa Konsentrasi NaOH dan Temperatur Pemanasan Terhadap Kadar Selulosa dan Kadar Lignin dari Batang Pisang Klutuk Menggunakan Alat Delignifikasi sebagai Bahan Baku Pembuatan Bioetanol.

Indonesia is a country with the largest energy consumption in southeast asia and fifth in asia pacific in primary energy consumption, after a chinese, india, japan, and south korea. If considered sectorally, so having the greatest share of the transportation sector, is as much as 42%, higher than the industrial sector with of 36. Hence the need of the use of environmentally friendly alternative energy and new and renewable energy ( ebt bioetanol ) as. Bioetanol can come from organic waste as klutuk stems of a banana tree. To research it will study and to making delignifikasi adsorbsi klutuk bioetanol of a banana stem. To research will be done study delignifikasi and adsorbsi to making bioetanol of a banana stem klutuk. First, perform the process pratreatmen and delignifikasi in a banana stem klutuk with variations konsetrasi naoh 10%, 20%, 30% and temperature warming namely 100oC, 125oC, 150oC, 175oC, and 100oC. At the delignifikasi this can be said that on the concentration naoh 10% in 150oC, warming temperatures produce levels of cellulose and lignin best, to the cellulose and lignin 81,3% levels 10,1%. A banana stem fiber that has been in delignifikasi, next will be done and also hydrolysis fermentation to produce bioetanol. Bioetanol produced the application will be done distillation to separate bioetanol and water. Bioetanol next analysis used a gcms and obtained bioetanol 80,34%.

Construction of the SHP-GLOX lignin regulation system and its application in rice straw

BackgroundThere is great productivity of rice(Oryza sativa L. spp. japonica) straw in China, which is a potential source of biomass for biofuel and forage. However, the high levels of lignins in rice straw limited its usage and induced the formation of agricultural waste. In order to modify the lignins contents to improve biofuel production and forage digestibility, we selected Soybean hull peroxidase (SHP) and Glyoxal oxidase (GLOX) as candidate genes to improve quality of rice straw. SHP, a class III plant peroxidase, is derived from multiple sources. It has several advantages, such as high resistance to heat, high stability under acidic and alkaline conditions, and a broad substrate range. SHP is speculated to be useful for lignin degradation. Glyoxal oxidase (GLOX) is an extracellular oxidase that can oxidize glyoxal and methylglyoxal in the extracellular medium to generate H2O2.ResultsIn the present study, the SHP and GLOX genes in pCAMBIA3301-glycine-rich protein (GRP)-SHP-GLOX, designated the K167 vector, were optimized and introduced into rice embryos using Agrobacterium-mediated transformation. Positive transgenic rice embryos were examined using molecular, physiological, biochemical and fermentation tests. The outcomes suggested that SHP degraded lignin effectively.ConclusionsThis research has created a rice breeding material with normal growth and yield but stalks that are more amenable to degradation in the later stage for use in breeding rice varieties whose stalks are easily used for energy. Our results will improve the industrial and commercial applications of rice straw.

Utilization of the antagonistic yeast, Wickerhamomyces anomalus, combined with UV-C to manage postharvest rot of potato tubers caused by Alternaria tenuissima

Postharvest rot of potato tubers caused by fungal pathogens is the main cause of significant economic losses, while also raising potential food safety issues. Integrated disease management, utilizing bio-safe and eco-friendly methods, represents a sustainable strategy for reducing postharvest losses in crops, including potato. In the current study, the application of the antagonistic yeast, Wickerhamomyces anomalus, combined with a UV-C treatment was evaluated for the management of postharvest Alternaria rot of potato tubers, caused by Alternaria tenuissima. Both W. anomalus and UV-C as individual treatments reduced the size of A. tenuissima infections on potato tubers, relative to the control, while the combined treatment of W. anomalus and UV-C exhibited the highest level of inhibition. W. anomalus or UV-C alone, and especially when used in combination, induced the expression of defense-related genes, including polyphenol oxidase, peroxidase, and β-1,3-glucanase, and also increased the level of flavonoids and lignin in potato tubers. Our findings indicate that the mechanism of action by which UV-C enhances the biocontrol effect of W. anomalus against postharvest Alternaria rot includes the activation of defense-related response in potato tubers. The integration of biocontrol agents and physical treatments (e.g., UV-C) represents an effective, eco-friendly hurdle technology for managing postharvest rot in potato.

A phenylalanine ammonia lyase from Fritillaria unibracteata promotes drought tolerance by regulating lignin biosynthesis and SA signaling pathway

Drought is one of the key threatening environmental factors for plant and agriculture. Phenylalanine ammonia lyase (PAL) is a key enzyme involved in plant defense against abiotic stress, however, the role of PAL in drought tolerance remains elusive. Here, a PAL member (FuPAL1) containing noncanonical Ala-Ser-Gly triad was isolated from Fritillaria unibracteata, one important alpine pharmaceutical plant. FuPAL1, mainly distributed in cytosol, was more conserved than FuCOMT and FuCHI at both nucleotide and amino acid levels. FuPAL1 was overexpressed in Escherichia coli and the purified recombinant FuPAL1 protein showed catalytic preference on L-Phe than L-Tyr. Homology modeling and site-mutation of FuPAL1 exhibited FuPAL1 took part in the ammonization process by forming MIO-like group, and Phe141, Ser208, Ileu218 and Glu490 played key roles in substrate binding and (or) catalysis. HPLC analysis showed that lignin and salicylic acid levels increased but total flavonoid levels decreased in FuPAL1 transgenic Arabidopsis compared to wild-type plants. Moreover, FuPAL1 transgenic Arabidopsis significantly enhanced its drought tolerance, which suggested that FuPAL1 mediated tolerance to drought by inducing the biosynthesis and accumulation of salicylic acid and lignin. Taken together, our results confirmed that the FuPAL1 played an important role in drought tolerance, and FuPAL1 might be a valuable target for genetic improvement of drought resistance in future.

Single-walled carbon nanotubes promotes wood formation in Populus davidiana × P.bolleana

Abundant studies have revealed that single-walled carbon nanotubes (SWCNTs) regulate plant growth. However, whether or how SWCNTs influence plant wood formation remains largely unknown. In this report, we found that SWCNTs had positive effects on poplar growth, as reflected by significantly increased plant height, leaf size, and fresh and dry weight. Transmission electron microscopy (TEM) images showed that the SWCNTs were absorbed in the exposed poplar root cells. A relatively higher content of cellulose and lignin was observed in the SWCNTs-treated poplar stems than in those of the control plants. It also showed darker phloroglucinol staining in the stems of exposed plants than that in control plants. Further analysis showed that the activities of key enzymes related to cellulose synthesis (cellulose synthase, CesA) and lignin biosynthesis (phenylalanine ammonia-lyase, PAL; cinnamate 4-hydroxylase, C4H; 4-coumarate:CoA ligase, 4CL; cinnamyl alcohol dehydrogenase, CAD) increased significantly after SWCNTs treatment. Consistent with the change trend of enzyme activity, the relative expression levels of a few lignin- and cellulose-related genes were activated by SWCNTs. Taken together, we proposed that SWCNTs have positive effects on poplar wood formation by modifying the expression of enzymes involved in the cellulose and lignin synthesis pathways. Our data suggest the modifications of wood formation through SWCNTs application could be a useful strategy for improvement of wood bioengineering.

Molecular and biochemical characterization of two 4-coumarate: CoA ligase genes in tea plant (Camellia sinensis).

Two 4-coumarate: CoA ligase genes in tea plant involved in phenylpropanoids biosynthesis and response to environmental stresses. Tea plant is rich in flavonoids benefiting human health. Lignin is essential for tea plant growth. Both flavonoids and lignin defend plants from stresses. The biosynthesis of lignin and flavonoids shares a key intermediate, 4-coumaroyl-CoA, which is formed from 4-coumaric acid catalyzed by 4-coumaric acid: CoA ligase (4CL). Herein, we report two 4CL paralogs from tea plant, Cs4CL1 and Cs4CL2, which are a member of class I and II of this gene family, respectively. Cs4CL1 was mainly expressed in roots and stems, while Cs4CL2 was mainly expressed in leaves. The promoter of Cs4CL1 had AC, nine types of light sensitive (LSE), four types of stress-inducible (SIE), and two types of meristem-specific elements (MSE). The promoter of Cs4CL2 also had AC and nine types of LSEs, but only had two types of SIEs and did not have MSEs. In addition, the LSEs varied in the two promoters. Based on the different features of regulatory elements, three stress treatments were tested to understand their expression responses to different conditions. The resulting data indicated that the expression of Cs4CL1 was sensitive to mechanical wounding, while the expression of Cs4CL2 was UV-B-inducible. Enzymatic assays showed that both recombinant Cs4CL1 and Cs4CL2 transformed 4-coumaric acid (CM), ferulic acid (FR), and caffeic acid (CF) to their corresponding CoA ethers. Kinetic analysis indicated that the recombinant Cs4CL1 preferred to catalyze CF, while the recombinant Cs4CL2 favored to catalyze CM. The overexpression of both Cs4CL1 and Cs4CL2 increased the levels of chlorogenic acid and total lignin in transgenic tobacco seedlings. In addition, the overexpression of Cs4CL2 consistently increased the levels of three flavonoid compounds. These findings indicate the differences of Cs4CL1 and Cs4CL2 in the phenylpropanoid metabolism.

Nitrogen fertilization strategies with protected urea for tropical grasses in an integrated crop-livestock system

The intercropping of corn and grass allows for the production of grains, and simultaneously, the recuperation and renovation of pastures. This study aimed to evaluate the effects of N doses on the yield, structure, chemical-bromatological characteristics, and the N use efficiency of Brachiara brizantha cultivars in an integrated crop-livestock system. The experimental design was completely randomized, with four replications, in a slip-plot scheme. The plots were formed of two grass plants, Marandu and Paiaguás, intercropped with corn and subplots composed of nitrogen doses (70, 100, and 130 kg N ha-1). During the system’s establishment (1st cycle), the Paiaguás grass presented higher values for all morphogenic and structural characteristics and higher forage yield when compared to Marandu grass. After the corn harvest, the interaction effect of the N doses and the cultivars for the foliar structure emergence and the number of living leaves was observed. The variables foliar elongation rate, stem elongation rate, and phyllochron were not influenced by any of the investigated factors (P>0.05). The highest DM content was obtained with the application of 100 kg ha-1 of N, whereas, for the other chemical characteristics, there was only an effect among the cultivars. Paiaguás grass exhibited the highest levels of NDF, ADF, lignin, and MM. CP levels were not influenced by the factors studied. Marandu grass and the use of 70 kg N ha-1 are recommended for intercropping with corn

Characterization of a Novel Creeping Tartary Buckwheat (Fagopyrum tataricum) Mutant lazy1.

Gravity is known as an important environmental factor involved in the regulation of plant architecture. To identify genes related to the gravitropism of Tartary buckwheat, a creeping line was obtained and designated as lazy1 from the mutant bank by 60Co-γ ray radiation. Genetic analysis indicated that the creeping phenotype of lazy1 was attributed to a single recessive locus. As revealed by the horizontal and inverted suspension tests, lazy1 was completely lacking in shoot negative gravitropism. The creeping growth of lazy1 occurred at the early seedling stage, which could not be recovered by exogenous heteroauxin, hormodin, α-rhodofix, or gibberellin. Different from the well-organized and equivalent cell elongation of wild type (WT), lazy1 exhibited dilated, distorted, and abnormally arranged cells in the bending stem. However, no statistical difference of indole-3-acetic acid (IAA) levels was found between the far- and near-ground bending sides in lazy1, which suggests that the asymmetric cell elongation of lazy1 was not induced by auxin gradient. Whereas, lazy1 showed up-expressed gibberellin-regulated genes by quantitative real-time PCR (qRT-PCR) as well as significantly higher levels of gibberellin, suggesting that gibberellin might be partly involved in the regulation of creeping growth in lazy1. RNA sequencing (RNA-seq) identified a number of differentially expressed genes (DEGs) related to gravitropism at stages I (before bending), II (bending), and III (after bending) between WT and lazy1. Venn diagram indicated that only Pectate lyase 5 was down-expressed at stages I [Log2 fold change (Log2FC): −3.20], II (Log2FC: −4.97), and III (Log2FC: −1.23) in lazy1, compared with WT. Gene sequencing revealed that a fragment deletion occurred in the coding region of Pectate lyase 5, which induced the destruction of a pbH domain in Pectate lyase 5 of lazy1. qRT-PCR indicated that Pectate lyase 5 was extremely down-expressed in lazy1 at stage II (0.02-fold of WT). Meanwhile, lazy1 showed the affected expression of lignin- and cellulose-related genes and cumulatively abnormal levels of pectin, lignin, and cellulose. These results demonstrate the possibility that Pectate lyase 5 functions as the key gene that could mediate primary cell wall metabolism and get involved in the asymmetric cell elongation regulation of lazy1.

Lignin decomposition of Oil Palm Frond by Pleurotus ostreatus with a variation of corn and rice-husk media

This study aimed to decompose lignin from oil palm midrib (OPF) bonds using the fungus Pleurotus ostreatus with various substrates (corn and rice husk). Lignin and cellulose levels before and after mushroom culture were tested by the Chesson-Datta method. Substrate variation with corn and husk rice showed that the addition of corn did not play a role in lignin decomposition. After being given treatment, the best degradation was using 0.6 grams of rice bran and 0.4 grams of CaCO3, 22.01% for lignin and 32.74% for cellulose.

Silicon Nanoparticles Enhance Ginger Rhizomes Tolerance to Postharvest Deterioration and Resistance to Fusarium solani.

Postharvest deterioration of ginger rhizome caused by microorganisms or wound infections causes significant economic losses. Fusarium solani is one of the important causal agents of prevalent ginger disease soft rot across the world. The massive and continuous use of chemical fungicides in postharvest preservation pose risks to human health and produce environmental contamination. Hence, new alternative tools are required to reduce postharvest deterioration and extend the postharvest life of ginger. In this study, the use of silicon nanoparticles (SiNPs) on the storability of ginger rhizomes during postharvest storage and their resistance to Fusarium solani was investigated. The results showed that 50, 100, and 150 mg L−1 of SiNPs increased the firmness of the ginger rhizome during storage but decreased the decay severity, water loss, total color difference, and the reactive oxygen species (ROS; H2O2 and superoxide anion) accumulation. Specifically, 100 mg L−1 (SiNP100) demonstrated the best effect in the extension of postharvest life and improved the quality of the ginger rhizomes. SiNP100 application increased the activities of antioxidant enzymes (SOD and CAT) and the total phenolics and flavonoid contents, thereby reducing the ROS accumulation and malondialdehyde (MDA) content. Meanwhile, SiNP100 treatment negatively impacts the peroxidase (POD) and polyphenol oxidase (PPO) activities, which may have contributed to the lower level of lignin and decreased total color difference. SiNP100 likely decreased water loss and the transfer of water by altering the expression of aquaporin genes. Moreover, SiNP100 modulated the expression of lignin synthesis and phytopathogenic responses genes including MYB and LysM genes. Furthermore, SiNP100 inhibited Fusarium solani by preventing the penetration of hyphae into cells, thus decreasing the severity of postharvest pathogenic decay. In summary, this study revealed the physiology and molecular mechanisms of SiNPs-induced tolerance to postharvest deterioration and resistance to disease, which provides a foundation for using SiNPs resources as a promising alternative tool to maintain ginger quality and control postharvest diseases.

Preharvest multiple sprays with chitosan promotes the synthesis and deposition of lignin at wounds of harvested muskmelons

As an important elicitor, chitosan could activate the synthesis of lignin in many plants. However, no report is available on whether preharvest chitosan sprays affects the synthesis and deposition of lignin at wounds of harvested muskmelons. In the present study, the plants and fruit of muskmelons were multiple sprayed with 0.1% chitosan during fruit development. Here, we found that chitosan sprays increased the activities of 4-coumaric acid-coenzyme A ligase, cinnamyl-CoA reductase and cinnamyl alcohol dehydrogenase, and elevated the levels of p-coumaryl alcohol, coniferyl alcohol, sinapyl alcohol and lignin at wounds. Chitosan sprays enhanced H2O2 level and peroxidase activity, and accelerated the deposition of lignin at wounds. Moreover, chitosan sprays resulted in a higher hardness and lower resilience, springiness and cohesiveness of the healing tissues. Taken together, preharvest chitosan sprays accelerated the deposition of lignin at wounds of muskmelons by activating lignin metabolism, and increasing H2O2 content and peroxidase activity.

Identification of a novel laccase gene EuLAC1 and its potential resistance against Botrytis cinerea.

In this study, a novel laccase gene, EuLAC1, was cloned from Eucommia ulmoides Oliver (E. ulmoides). An overexpression vector harboring the EuLAC1 was constructed and introduced into the tobacco (Nicotiana tabacum cv. Xanthi). The laccase activity, resistance to Botrytis cinerea (B. cinerea) and lignin level in wild-type and transgenic plants were thereafter investigated. Interestingly, the transgenic tobacco displayed a significantly higher laccase activity and resistance to gray mold as compared to the wild-type tobacco. Additionally, the lignin contents in the leaves and stems of the transgenic tobacco were significantly higher in comparison to the wild-type tobacco. Scanning electron microscopy was used to observe the cross sections of wild-type and transgenic tobacco stems and it was noted that the cell wall near the xylem catheter of the transgenic tobacco was substantially thicker and the outline clearer than that of the wild-type. Thus, the EuLAC1 gene can significantly increase laccase activity and lignin content in tobacco, leading to an increase in the physical defenses, thereby increasing tobacco resistance to gray mold.

Cellulose Microfiber Encapsulated Probiotic: Viability, Acid and Bile Tolerance during Storage at Different Temperature

This work aimed to analyze the physicochemical properties of cellulose from OPT used in the fabrication of CMF and evaluate the efficacy of the hydrogel CMF as an encapsulant for L. fermentum InaCC B1295 stored at room temperature and in the refrigerator. The Kjeldahl method was used to evaluate the protein content; the gravimetric method was used to determine OPT's ash, moisture, and fiber contents; the Soxhlet method was used to determine the fat content carbohydrates were computed using the difference method. The levels of holocellulose, lignin, and cellulose were also determined. Viability, acid and bile resistance of strain B1295 were evaluated at various temperatures for 35 days. The most abundant component of OPT fiber was cellulose, followed by hemicellulose and lignin. XRD examination revealed that OPT cellulose has a crystal index of 83.40%. FTIR analysis was used to detect the stretching vibrations of the –OH group on cellulose at 3419.03 cm-1. CMF hydrogel from OPT sustained L. fermentum InaCC B1295 survival for up to 28 days at room and refrigerated temperatures. At acidic conditions and in the presence of bile, the viability of L. fermentum InaCC B1295 was excellent, with a drop in cell population of less than 0.2 log CFU/g over 35 days at room and refrigerated temperatures. CMF obtained from OPT can be used as an encapsulant to maintain viability, acid resistance and bile of probiotics. There is still a need for research into the usage of CMF from OPT in combination with other encapsulants to extend the storage life of L. fermentum InaCC B1295. Doi: 10.28991/ESJ-2022-06-01-08 Full Text: PDF

Screening coffee genotypes for brown eye spot resistance in Brazil.

Several researchers have attempted to develop coffee plants that are resistant to brown eye spot (BES); however, no coffee cultivars are resistant to the disease. In the present study, a blend of strains from Cercospora coffeicola was inoculated into 19 Brazilian commercial cultivars and 41 accessions from the Germplasm Collection of Minas Gerais to evaluate the genetic resistance ability within the population and select superior genotypes for the breeding program. After predicting the genotypic values of the estudied material, the evaluations number necessary for selecting genotypes with accuracy and efficiency was determined based on the data of severity to BES. The action of defense mechanisms plant was also investigated by assessing the levels of total soluble phenolic compounds and soluble lignin in contrasting genotypes for disease susceptibility. Based on the results, the accession MG 1207 Sumatra, had an intrinsic genetic capacity to maintain low levels of severity to BES. The genotype MG 1207 Sumatra can substantially contribute to the development of new cultivars, which may lead to the reduced use of pesticides. According to the accuracy and efficiency results obtained, four evaluations BES severity are sufficient to achieve accuracy, providing expressive genetic gains. Finally, the levels of lignin and phenolic compounds were not found to be associated with the resistance of coffee genotypes to BES.

Characterisation of Congolese Aquatic Biomass and Their Potential as a Source of Bioenergy

This study assesses the bioenergy potential of two types of aquatic biomass found in the Republic of Congo: the green macroalgae Ulva lactuca (UL) and Ledermanniella schlechteri (LS). Their combustion behaviour was assessed using elemental and biochemical analysis, TGA, bomb calorimetry and metal analysis. Their anaerobic digestion behaviour was determined using biochemical methane potential (BMP) tests. The average HHV for LS is 14.1 MJ kg−1, whereas UL is lower (10.5 MJ kg−1). Both biomasses have high ash contents and would be problematic during thermal conversion due to unfavourable ash behaviour. Biochemical analysis indicated high levels of carbohydrate and protein and low levels of lipids and lignin. Although the lipid profile is desirable for biodiesel production, the levels are too low for feasible extraction. High levels of carbohydrates and protein make both biomasses suitable for anaerobic digestion. BMP tests showed that LS and UL have an average of 262 and 161 mL CH4 gVS−1, respectively. The biodegradability (BI) of LS and UL had an average value of 76.5% and 43.5%, respectively. The analysis indicated that these aquatic biomasses are unsuitable for thermal conversion and lipid extraction; however, conversion through anaerobic digestion is promising.

Comparison of the Deep Euteutic Solvent (DES) Solvent for Extracting Lignin from the Lignocellulosic Material of Pineapple Leaves

Background: Lignocellulosic biomass is one of the materials that has the potential to produce cellulose. Lignocellulose material consists of lignin, hemicellulose and cellulose so that the three materials must be separated first to get pure cellulose. The main problem faced in the process of separating cellulose is the difficulty of separating lignin. One of the processes in separating lignin is by pretreatment of lignocellulosic material. Methods: In this study, Deep Euteutic Solvent (DES) choline (ChCl) as a hydrogen bond acceptor was synthesized and eight hydrogen bond donors (HBD) were mixed. Eight types of DESs, i.e. , choline chloride-acetic acid (ChCl-AA), ChCl: formic acid (ChCl-FA). ), choline chloride: Lactic acid (ChCl-LA), choline chloride:Citric acid (ChCl-SA), choline chloride: Glycerol (ChCl-G), choline chloride: Ethylenglycol (ChCl-EG), choline chloride: Sorbitol (ChCl-S), and choline chloride: Urea (ChCl -U) with a ratio of 1: 2 were investigated. Each. DES solvent was applied as a pretreatment for the lignocellulosic material of pineapple leaves. The results of the pretreatment formed were characterized by the Infra Red spectroscopic method to determine the typical functional groups. Result: The results showed that the pretreatment process using DES solvent resulted in a decrease in lignin levels in pineapple leaf powder, the highest in DES with linear saturated acid-based HBD, formic acid at 32.05%, glycerol at 30.18% and then in alpha hydroxy-based HBD, acetic acid at 29.90%. Meanwhile, the FT-IR results show that ChCl-FA has a high delignification ability during pretreatment. Pineapple leaves that have been pretreted with DES solvent can be a potential raw material for the next conversion process. This study presents DES as an effective and easy pretreatment method for lignin extraction.

Carbon reservoirs in shade-tolerant morphotype of Paubrasilia echinata are more susceptible to humidity and temperature changes than sun-tolerant morphotype

Given the eminent climate changes and the importance of carbon dynamics in the growth and survival of plants, we investigated how the non-structural carbohydrates – NSC – and cell wall polymers – CWP (cellulose, hemicellulose, and lignin) – from sun-tolerant and shade-tolerant plants will respond to changes in vapor pressure deficit (VPD) and temperature (temp.) of atmosphere predicted for the southeast region of Brazil for the next decades. We used plants of two morphotypes of Paubrasilia echinata as a biological model. This species presents intraspecific variations from each other in leaf morphology and growth concerning luminosity in the initial phase of growth. The small morphotype is shade-tolerant and the medium morphotype is tolerant to full sun. The work was carried out in greenhouses adjusted with the combination of the higher and lower VPD and temp., constituting 4 enviroments: 1) 0.4 KPa – 19.8 °C, 2) 0.5 KPa – 23.8 °C, 3) 2.0 KPa – 25.1 °C, and 4) 1.1 KPa – 14.9 °C. On day 125 after the start of the experiment, we determined the concentrations of NSC and CWP in the root, stem, and leaves. The shade-tolerant morphotype showed an increase in sugar concentration in the environment where the plants grew the most (2.0 KPa – 25.1 °C). In this same environment, the NSC concentrations of the shoot organs increased in the sun-tolerant morphotype. The 0.4 KPa – 19.8 °C reduced the cellulose and lignin concentrations of the shade-tolerant morphotype and promoted the hemicelluloses of the sun-tolerant morphotype. The NSC and CWP allocation proved to be more influenced by VPD and temp. variations in the shade-tolerant than the sun-tolerant morphotype. We conclude that warming and lower atmospheric humidity could inhibit the axial stem growth of sun-tolerant juvenile plants. Warming, regardless of atmospheric humidity variations, will not affect the cellulose and lignin levels of stem, and consequently, the wood quality of shade- and sun-tolerant plants. However, hemicelluloses concentrations of sun-tolerant plants may decline in a warmer and less humid atmosphere.

Cell wall modification and lignin biosynthesis involved in disease resistance against Diaporthe citri in harvested pummelo fruit elicited by carvacrol.

Phomopsis stem-end rot caused by Diaporthe citri, causes significant commercial postharvest losses of pummelo fruit during storage. Carvacrol (CVR) is a known generally recognized as safe and has the ability to prolong the preservation of harvested fruits. In the present study, the inhibitory effects of CVR treatment at the appropriate concentration on Phomopsis stem-end rot development of harvested pummelo fruit inoculated with D. citri were evaluated by the amounts of cell wall components, the activities and gene expressions of related enzymes involved in cell wall modification and lignin biosynthesis. Results indicated that CVR completely inhibited D. citri growth in vitro at 200 mg L-1 and significantly controlled Phomopsis stem-end rot development in harvested pummelo. The CVR treatment delayed peel softening and browning, and retarded electrolyte leakage, superoxide radical (O2 •- ) production, and malondialdehyde content. The CVR-treated fruit maintained higher amounts of cell wall material, protopectin, hemicelluloses, and cellulose, but exhibited lower water-soluble pectin amount. Moreover, in D. citri-inoculated fruit, CVR treatment suppressed the activities and gene expressions of cell wall disassembling-enzymes, including pectin methylesterase, polygalacturonase, cellulase, and β-galactosidase, while the development of cell wall degradation was reduced. Meanwhile, the CVR treatment enhanced the lignin biosynthesis by increasing the activities and up-regulating the gene expressions of phenylalanine ammonialyase, cinnamic alcohol dehydrogenase, and peroxidase accompanied with elevated level of lignin in pummelo fruit. The disease resistance to D. citri in pummelo fruit elicited by CVR treatment is related to delaying cell wall degradation and enhancing lignin biosynthesis. © 2021 Society of Chemical Industry.

Hypolignification: A Decisive Factor in the Development of Hyperhydricity.

One of the characteristics of hyperhydric plants is the reduction of cell wall lignification (hypolignification), but how this is related to the observed abnormalities of hyperhydricity (HH), is still unclear. Lignin is hydrophobic, and we speculate that a reduction in lignin levels leads to more capillary action of the cell wall and consequently to more water in the apoplast. p-coumaric acid is the hydroxyl derivative of cinnamic acid and a precursor for lignin and flavonoids in higher plant. In the present study, we examined the role of lignin in the development of HH in Arabidopsis thaliana by checking the wild-types (Ler and Col-0) and mutants affected in phenylpropanoid biosynthesis, in the gene coding for cinnamate 4-hydroxylase, C4H (ref3-1 and ref3-3). Exogenously applied p-coumaric acid decreased the symptoms of HH in both wild-type and less-lignin mutants. Moreover, the results revealed that exogenously applied p-coumaric acid inhibited root growth and increased the total lignin content in both wild-type and less-lignin mutants. These effects appeared to diminish the symptoms of HH and suggest an important role for lignin in HH.

ENZIMATIC HYDROLYSIS PROCESS FOR INCREASING GLUCOSE LEVELS FROM COCONUT HUSK WASTE

Coconut husk waste is waste that has not been used optimally, generally only as a craft material. Seeing the composition of coconut husk, it has the potential to be used as an alternative fuel, one of which is to produce bioethanol products. The purpose of this research was to utilize coconut husk waste as raw material for bioethanol production and to assess the effect of the number of enzymes and time of hydrolysis on the glucose levels produced. In this research, the authors focused on obtaining glucose levels from coconut husks by hydrolysis using cellulase enzymes with an activity of 700 EGU/g. The variations used in this research were the volume of cellulase enzymes (2, 3, 4, 5, 6) ml and the hydrolysis time (4, 8, 12) hours. After the coconut husk undergoes physical and chemical treatment using 10% NaOH, there is a decrease in lignin levels from 44% to 14% and there is an increase in cellulose levels from 24% to 38%, and the use of a cellulase enzyme volume of 2 ml with a hydrolysis time of 4 hours was more optimal with a glucose level of 0.32%.