Sugar Ratio Research Articles

Developing Fermentation Liquid of Bacillus amyloliquefaciens PMB04 to Control Bacterial Leaf Spot of Sweet Pepper

Sweet pepper is an important vegetable in the world. Bacterial leaf spot, caused by the pathogen Xanthomonas perforans, is a limiting factor that significantly reduces the quality and yield of sweet peppers. The use of chemical fungicides is currently the main disease-control method for bacterial leaf spot disease. It is important to develop an eco-friendly biocontrol method by using antagonistic microorganisms. Bacillus amyloliquefaciens PMB04 has strong antagonistic effects against pathogens and can inhibit the occurrence of diseases. B. amyloliquefaciens PMB04 has the potential for the development of a disease-control product. Primarily, PMB04 contained a strong inhibitory effect against all isolated X. perforans strains. In the inoculation assay, the severity of bacterial leaf spot disease on sweet peppers was reduced by PMB04 bacterial suspensions. To increase the convenience of field applications in future prospects, the development of the PMB04 fermentation liquid was carried out using different ratios of brown sugar and yeast extract in a 30 L fermentation tank. The results exhibited that the fermentation liquid of the 3-1 and 2-1 formulas obtained the highest bacterial population in a 30 L fermentation tank. The fermentation liquid of the 0.5-0.5 formula was the most stable formula for two different conditions in terms of a consistent bacterial population and sporulation. In addition, the 200-fold dilution of the 3-1 and 0.5-0.5 fermentation liquids revealed the best control efficacy on bacterial leaf spot disease of sweet peppers. Additionally, the results of the 0.5-0.5 fermentation liquid (PMB4FL) with different dilution concentrations also demonstrated that the 200- and 500-fold dilutions had the best control efficacy. To understand the effect of commonly used copper-containing fungicides on sweet peppers on the application of microbial agent PMB4FL, the effects of copper hydroxide and tribasic copper sulfate on the growth of X. perforans strains and B. amyloliquefaciens PMB04 were assayed. The results exhibited that the above two fungicides did not have any inhibitory effect on the growth of PMB04 but had a strong inhibitory effect on the X. perforans strain. In the follow-up control experiment, the treatment of copper hydroxide had no synergistic effect with PMB4FL to control bacterial leaf spot disease. We concluded that the use of the PMB4FL fermentation liquid alone on the leaves could effectively control the occurrence of bacterial leaf spots in sweet pepper crops.

Some Economic Aspects of Sugar as a Strategic Commodity in Egypt

The research aims mainly to study Egyptian food security of sugar through studying of several sub-objectives represented in: estimating some economic indicators of sugar in Egypt during the period (2008- 2020), studying of the most important indicators of food security of sugar, estimating the size of the food gap of sugar and knowledge of the most important factors responsible for, and studying the policies and means to achieve food security of sugar in Egypt. Descriptive and quantitative analysis were used. The study depends on secondary data, which collected from local and foreign sources during the period (2008- 2020). The conduct study shows that the most important variables specific to the food gap of sugar are all from the local production of sugar and domestic consumption of sugar where it was found that the impact of each of these two variables on sugar gap be negative. The study showed that the strategic stock of sugar is estimated at 1.15 million tons and the average national consumption of sugar is estimated at 2.17 million tons during the study period (2008-2020) with an annual average during that period , therefore, coefficient of sugar food security estimated at about 0.37, therefore it requires to take various actions that would lead to increase the size of the sugar strategic stock to enough half of it needs for domestic consumption even come close to the value of coefficient of food security, from suitable coefficient of sugar food security. The study showed that the policies and means to achieve sugar food security include horizontal agricultural development policy, vertical agricultural development policy, the policy of rationalizing the consumption of sugar, policy of consumer subsidy of sugar, and the policy of diversifying sources of imported sugar. In the light of the results of the study illustrated by research it has been possible to reach some of the following recommendations: 1- It is necessary to intensify efforts to agricultural extension and agricultural research centers in collaboration with factories engineers and agriculture departments and supervisors agricultural awareness of the importance of agriculture resistance to pests and diseases that affect the crop, and help them get on pesticides is harmful to the environment to do so. 2- Increasing of sugar production through the expansion of sugar crops, particularly sugar beet to the lack of water needs compared to sugar cane harvest in the new land. 3- Increasing of sugar productivity crops through dissemination of sugar varieties of high productivity and to suit every center of administrative centers in Egypt. 4- Rationalizing the consumption of sugar during dismiss the size of the loss of sugar. 5- to achieve food security has to be the need to develop awareness programs for the application of planning policy breeds where it is one of the most important determinants of the demand for i Egyptian imports of sugar. 6- it is important to put a national strategy to increase the self-sufficiency ratio of sugar with the need to import and distribute the amounts of diversification between different sources in order to avoid what might happen from political pressure in favor of the Egyptian economy is in the case of international political conditions change. 7- It is necessary to study the reduction commitments of support granted to the production and export in the sugar-exporting countries in order to reduce the negative effects on the Egyptian Saving.

Predicting the Quality of Tangerines Using the GCNN-LSTM-AT Network Based on Vis–NIR Spectroscopy

Fruit quality assessment plays a crucial role in determining their market value, consumer acceptance, and post-harvest management. In recent years, spectroscopic techniques have gained significant attention as non-destructive methods for evaluating fruit quality. In this study, we propose a novel deep-learning network, called GCNN-LSTM-AT, for the prediction of five important parameters of tangerines using visible and near-infrared spectroscopy (Vis–NIR). The quality attributes include soluble solid content (SSC), total acidity (TA), acid–sugar ratio (A/S), firmness, and Vitamin C (VC). The proposed model combines the strengths of graph convolutional network (GCN), convolutional neural networks (CNNs), and long short-term memory (LSTM) to capture both spatial and sequential dependencies in the spectra data, and incorporates an attention mechanism to enhance the discriminative ability of the model. To investigate the effectiveness and stability of the model, comparisons with three traditional machine-learning algorithms—moving window partial least squares (MWPLS), random forest (RF), and support vector regression (SVR)—and two deep neural networks—DeepSpectra2D and CNN-AT—are provided. The results have shown that the GCNN-LSTM-AT network outperforms other algorithms and models, achieving accurate predictions for SSC (R2: 0.9885, RMSECV: 0.1430 ∘Brix), TA (R2: 0.8075, RMSECV: 0.0868%), A/S (R2: 0.9014, RMSECV: 1.9984), firmness (R2: 0.9472, RMSECV: 0.0294 kg), and VC (R2: 0.7386, RMSECV: 29.4104 mg/100 g) of tangerines.

Type B trichothecenes in cakes and their interaction with matrix components

The study evaluated the detectable type B trichothecenes (TCTB) in cakes with different formulations in order to analyse their interaction with matrix components and the impact of daily exposure to these mycotoxins by cake consumption. A central composite design was carried out with the variables type of wheat flour (wholemeal and white flour) and ratios of milk, water and sugar. The TCTB reductions were correlated with the matrix components by principal component analysis (PCA) and the daily exposure was estimated in the condition that promoted the higher TCTB mitigation. The natural contamination of wheat flour, the ingredients dilution effect and the partial replacement of water by milk affected the TCTB levels in wholemeal cake (<1500 μg/kg) and white cake (<320 μg/kg). The PCA showed that the resistant starch was correlated with the TCTB detectable. The ingredients combination that promoted TCTB reductions of 68.9% in the white cake and 78.8% in the wholemeal cake, was the formulation that used 70 g of sugar and partial substitution of water by milk (20:20, mL/mL) in relation to 100 g of wheat flour. The daily exposure estimated by consumption of wholemeal cake was 3.5 times higher in comparison to white cake. The use of ingredients that lead to high resistant starch formation is a promising mitigation strategy.

Value Addition and Standardization of Recipe on Dragon Fruit Jelly (Hylocerous undatus L.)

The present investigation entitled “Value addition and standardization of recipe on dragon fruit jelly (Hylocerous undatus L.)” was conducted at Post-Harvest Laboratory of Department of Horticulture, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj during the year 2022. The experiment was laid down in Complete randomized design (RBD) with 3 replications and 10 treatments viz . T0 = (Control) Dragon fruit extract 1000ml+sugar 550g, T1 =Dragon fruit extract 1000ml + Mint 2.5g + sugar 550g T2 =Dragon fruit extract 1000ml + Mint 5g + sugar 550g , T3 =Dragon fruit extract 1000ml + Mint 7.5g + sugar 550g, T4 =Dragon fruit extract 1000ml + Cardamom 2g + Sugar 550g, T5= Dragon fruit extract 1000ml + Cardamom 3g + Sugar 550g, T6 = Dragon fruit extract 1000ml + Cardamom 4g + Sugar 550g, T7 = Dragon fruit extract 1000ml + Ginger 2.5g + Sugar 550g, T8 =Dragon fruit extract 1000ml + Ginger 5g + Sugar 550g and T9 =Dragon fruit extract 1000ml + Ginger 7.5 g + Sugar 550g. Study results revealed that, there was significant statistical variation TSS(ºBrix), Reducing Sugar(%), Non Reducing Sugar( %), total Sugar(%), titrable acidity (%), pH, ascorbic acid( mg/100gm), and Benefit cost Ratio. Maximum TSS (67.01 ºBrix), pH (4.41), Reducing Sugar(36.16 %), Non reducing Sugar (53.92%), Total sugar (72.08%), Titratable acidity (0.62%), Ascorbic acid (2.44mg/100gm), Colour appearance (8.45), Consistency (8.26), flavour and Taste (8.67), Aroma (6.07), overall acceptability (8.58), transparency (8.34), shelf-life 89.65) and benefit cost ratio 2.33 was recorded in T6 = Dragon fruit extract 1000ml + Cardamom 4g + Sugar 550g. Basis on this study Treatment T6 can be suggested to farmers to obtain better quality and higher benefit in jelly production.

Comparative evaluation of natural and artificial sweeteners from DNA damage, oxidative stress, apoptosis, to development using Drosophila melanogaster

The overconsumption of added sugars makes people vulnerable to a myriad of diseases. Several biochemical and developmental assays were performed in the current study to assess the effect of fructose on Drosophila melanogaster and to find substitutes for fructose by comparing it to well-known sweeteners. Drosophila was exposed separately to the same ratio of sugar 9.21% (w/v) of several types of sweeteners (sucrose, fructose, glucose syrup, high-fructose corn syrup and stevia). Results revealed that fructose might induce recombination, whereas stevia lacks genotoxic potential. No developmental delay, growth defects, or neurotoxic effects were recorded for any of the sweeteners. We also observed no striking differences in reactive oxygen species levels. Thus, stevia seems to be an alternative sweetener to fructose that can be consumed to reduce fructose-induced anomalies.

Quality of peda prepared from mawa with different sugar levels

Peda is a highly nutritious indigenous milk product of Bangladesh containing milk solids added sugar and other additive like cardamom powder. This experiment was conducted to test the feasibility of using mawa (dried milk) for making peda and also conducted to test the impact of sugar level on the quality of peda. Sugar, as traditional sweetener was used to make peda samples at the level of 0 g, 75 g, 150 g and 225 g. Peda samples were prepared with these different sugar ratios were analyzed for sensory attributes, chemical composition and microbiological quality. Analysis of the data for quality such as flavor, body and consistency, color and appearance and chemical analysis such as protein content, carbohydrate content, ash and total solids contents of peda samples revealed significant (P&lt;0.05) difference, but there was no significant (P&gt;0.05) differences for fat content and total viable count of peda samples. The organoleptic quality of 150 g sugar containing peda samples scored better result than control and other treatments. If overall quality aspects were considered, 150 g sugar containing peda samples gave best results than other samples. Asian Australas. J. Food Saf. Secur. 2023, 7 (2), 56-61

Correlation of lactulose-to-mannitol ratios in plasma and urine for intestinal permeability assessment in pigs.

The lactulose-to-mannitol ratio test is a test to assess the disorders associated with gut permeability. The test requires an oral administration of the mixture of lactulose and mannitol and urine collection. The urinary ratio of lactulose to mannitol is an indicator of intestinal permeability. Due to the complexity of urine collection in animal studies, plasma exposure ratios of lactulose to mannitol compared to their urinary concentration ratios were evaluated following an oral administration of the sugar mixture in pigs. 10 pigs were orally dosed with a solution of lactulose and mannitol mixture. Plasma samples were collected at predose, 10 and 30 minutes and 2, 4, and 6 hours postdosing, and cumulated urinary samples were collected at 6 hours for liquid chromatography-mass spectrometry analysis. The ratios of pharmacokinetic parameters of lactulose to mannitol and the plasma sugar ratios at a single time point or the mean values of several time points were compared to their urinary sugar ratios. The results revealed that the lactulose-to-mannitol ratios of AUC0-6h, AUCextrap, and Cmax were correlated to the urinary sugar ratios, and the plasma sugar ratios of a single time point at 2, 4, or 6 hours and the mean values of those time points were also appropriate to replace their urinary ratios in pigs. Following an oral administration of lactulose and mannitol mixture, blood collection, and assay can be an option for assessing intestinal permeability, especially in animal studies.

New Insight on In Vitro Biological Activities of Sulfated Polysaccharides from Ulvophyte Green Algae.

Green algae are natural bioresources that have excellent bioactive potential, partly due to sulfated polysaccharides (SPs) which are still rarely explored for their biological activities. There is currently an urgent need for studies exploring the anticancer biological activity of SPs extracted from two Indonesian ulvophyte green algae: the sulfated polysaccharide of Caulerpa racemosa (SPCr) and the sulfated polysaccharide of Caulerpa lentillifera (SPCl). The method of isolating SPs and their assessment of biological activities in this study were based on previous and similar studies. The highest yield sulfate/total sugar ratio was presented by SPCr than that of SPCl. Overall, SPCr exhibits a strong antioxidant activity, as indicated by smaller EC50 values obtained from a series of antioxidant activity assays compared to the EC50 values of Trolox (control). As an anti-obesity and antidiabetic, the overall EC50 value of both SPs was close to the EC50 of the positive control (orlistat and acarbose). Even more interesting was that SPCl displayed wide-ranging anticancer effects on colorectal, hepatoma, breast cancer cell lines, and leukemia. Finally, this study reveals new insights in that SPs from two Indonesian green algae have the potential to be promising nutraceuticals as novel antioxidative actors, and to be able to fight obesity, diabetes, and even cancer.

Reducción del número de semillas en mandarina “Yashar” mediante la aplicación de sulfato de cobre y diversas fuentes de granos de polen

The citrus trade market welcomes cultivars with different characteristics such as being totally seedless or having fewer seeds, having thin and vividness skin, high ratio of sugar to acid, being watery, easy peeling and relatively large fruit. Furthermore, a wide range of cultivars should be available according to fruit ripening time from very early (precocious) to very late (serotinous). ‘Yashar’ mandarin is a hybrid obtained by crossing of the ‘Minneola’ tangelo and ‘Changsha’ mandarin. The fruits of this cultivar grow in the northern regions of Iran, and it ripen in May, thus, they are considered the late-ripening mandarin cultivars. One of the deficiencies of this cultivar is that it is full of seeds (25-30). Two separate experiments were performed to reduce the number of seeds in ‘Yashar’ mandarin. In the first experiment; the effect of pollen grains of different citrus cultivars (‘Valencia’ orange, ‘Hamlin’ and sour orange) and a free-pollination treatment as a control group was evaluated. In the second experiment, the effect of foliar application of copper sulfate at the rate of 25 mg·L-1 was conducted in stages 30, 60 and 80 % of open flowers. One free pollination treatment as a control group was evaluated as well. The results showed that the highest index of fruit technology (multiplication of the percentage of the extract in the soluble solids divided by 100) was obtained by pollination with ‘Hamlin’ and sour orange pollen grains. The foliar spraying with copper sulfate, when 30 % of the flowers had opened, among all the treatments evaluated in the study, reduced the number of seeds in the Yashar mandarin cultivar.

Impact of Some Enzymatic Treatments on Acrylamide Content in Biscuits

Since its discovery in many heat-treatment foods in 2002, many efforts have been made to reduce acrylamide levels in foods. Methods to reduce acrylamide levels by reducing Maillard reaction products have been considered. However, baking cookies produces acrylamide, a carcinogenic compound. This study aimed to use a new quantitative index and formula for L-asparaginase, glucose oxidase, their 1:1 blending enzymes, baker’s yeast, and green tea powder (0.5 g/kg wheat flour) at a new proposed temperature of 37 °C for 30 min to reduce acrylamide production in biscuits and bakery products using new indicators such as asparagine reduction (%), the asparagine/acrylamide ratio, acrylamide reduction (%), and the asparagine/reducing sugar ratio. The highest acrylamide concentrations were reduced from 865 mg/kg in the blank sample (BT0) to 260 and 215 mg/kg in the mixed enzyme powder (1:1) (BT3)- and BT4-treated samples, respectively. The biscuit samples treated with 0.5 g/kg L-asparaginase reduced the acrylamide levels by approximately 67.63%, while the BT3 samples showed acrylamide levels of 69.94% and asparagine levels of 68.75% and 47%, respectively, compared with percentage in the untreated sample (blank), 95%. This percentage was 54.16% for the BT4 samples. The results showed that acrylamide was formed during baking, and all treatment samples inhibited its formation, making it possible to produce foods with low levels of acrylamide in starchy foods in the food industry at 37 °C for 30 min and preserving the quality and nutritional value of the final product. It can be used as a specialty food or functional food and protects school-agechildren, as well as youth on campus, from approximately 70–80% of their daily intake of acrylamide.

Changes in the structure of polysaccharides under different extraction methods

Changes in the structure of polysaccharides under different extraction methods

Investigation of the possibilities of using oleaster fruit flour in the production of low-fat- low-cholesterol mayonnaise

The aim of the study is to investigate the possible usage of oleaster fruit flour (OFF) (Elaeagnus angustifolia) in mayonnaise formulation by reducing the fat and egg yolk ratios. Mayonnaise samples with four different formulations as control, low-fat low-cholesterol mayonnaise-I (LFCM-I), low-fat low-cholesterol mayonnaise-II (LFCM-II) and low-fat low-cholesterol mayonnaise-III (LFCM-III) were produced. The oil, egg yolk and sugar ratios were decreased with the incremental percentage of OFF. The substitution of egg yolk and fat in the mayonnaise formula by the addition of OFF caused an increase in pH value, viscosity, firmness, consistency and work of shear, whereas a decrease in the acidity, total cholesterol content, peroxide value, TBARs value and conjugated dienes ratio. Considering all of the physical and chemical analysis results, the OFF can be used as a fat and egg yolk substitute in the mayonnaise formula; however, it was concluded that the mayonnaise-like sauce, which has higher emulsion stability and better physical characteristics, can be obtained by combining OFF with various stabilizers.

Prediction of Maple Syrup Quality from Maple Sap with a Plasmonic Tongue and Ordinal Mixed-Effects Modeling

A gold nanoparticle (Au NP)-based plasmonic tongue is shown to correlate well with the emergence of flavor defects in the late season harvest of maple syrup, validated with a representative sampling of 29 304 maple syrups of different grades. The daily average temperatures, pH, transmittance, °Brix, and total and individual amino acid concentrations provided evidence that the plasmonic tongue responds to amino acid concentrations, which is then correlated to an off-flavor index. The amino acid to sugar ratio decreased significantly in syrup compared to sap, a result of their consumption in the Maillard reaction during the boiling process. An ordinal mixed-effect model was shown to accurately predict the amino acid concentrations and the most likely grading class of maple syrup from the plasmonic tongue’s response. Taken together, the plasmonic tongue with the mathematical model could serve as a predictor of the output quality of maple syrup from maple sap at the production site.

Powder Qualities of Foam-Mat Dried Mango

The objectives of this study are to demonstrate powder qualities of foam-mat dried mango using different foaming agents and then compare mango powder qualities of foam-mat drying method to that of the studies in other drying methods. Fresh puree of Mahajanaka mango (Mangifera indica L.) grown in the north of Thailand is mixed with glyceryl monostearate (GMS), sugar and soybean isolated (SBI) in different ratios as foaming agents, after that is dried at 70 °C in a tray dryer for 5 h. The color and % foam overrun revealed that GMS with sugar treatments contribute a decent quality more than that with SBI. Therefore, powder qualities of foam-mat dried mango using GMS with sugar are analyzed. Different ratios of GMS and sugar are not affected by their moisture content, solubility, and hygroscopicity values. The best powder quality is found when added 1 % GMS with 5 % sugar during storage at 90 %RH, and 38 ± 2 °C. Comparing the foam-mat dried mango qualities to other drying methods. It was found that foam-mat dried mango indicated a similarity appearance and moisture to spray dried and freeze-dried mango. The disadvantage of foam-mat drying method is a lowest solubility and hygroscopicity, but the more advantage of this method could be a low operation and maintenance cost. Therefore, good qualities of foam-mat dried mango powder with a cost-effective production would be a commercial potential for small-medium enterprise or community enterprise utilization. HIGHLIGHTS Mango powder qualities produced by a foam-mat drying as good as that 1 manufacturing using freeze drying and spray drying Foam-mat drying technology is a cost-effective production proper for a small-medium community enterprise especially in Thailand Foam-mat mango powder can apply for ingredients in a food manufacturing such as bakery, ice-cream, instant drinking and so on. This could be created mango usage diversity GRAPHICAL ABSTRACT

Sugar and Organic Acid Content Is Dependent on Tomato (Solanum Lycoperiscum L.) Peel Color

The sensory properties of fruit and vegetables are a result of taste and aroma caused by many volatile and nonvolatile compounds. The sum of organic acids (malic and citric acids) and soluble sugars (fructose and glucose), as well as their balanced combination and interaction, contributes to the characterization of the tomato flavour. The ratio of sugars and organic acids is the key to the sweetness and sourness of tomatoes. This study aimed to determine the sugar and organic acid content, as well as several physicochemical parameters, of eight tomato landraces from Croatia. All the parameters investigated differed between the tomato landraces. The PLS-DA analysis showed that the most important parameters in tomato landrace discriminatory character are malic acid, fructooligosaccharide content, citric acid, dry matter. The results obtained show a significant positive correlation between tomato dry matter and sugar content. At the same time, fructose and sucrose content is negatively correlated with the green to red hue of tomato peel, as well as positively with the blue to yellow hue, indicating that the sugar content increases with yellow color intensity. The blue to yellow hue of the peel color also positively correlates with citric acid content.

Differentially expression analyses in fruit of cultivated and wild species of grape and peach

Through agronomic traits and sequencing data, the cultivated and wild varieties of grapes and peaches were analyzed and compared in terms of fruit size, fruit flavor, fruit resistance, and fruit color. Cultivated grapes and peaches have advantages in fruit size, soluble sugar content, sugar and acid ratio, etc. Wild grapes and peaches have utility value in resistance. The results showed that there were 878 and 301 differentially expressed genes in cultivated and wild grapes and peaches in the three growth stages, respectively based on the next-generation sequencing study. Ten and twelve genes related to the differences between cultivated and wild grapes and peaches were found respectively. Among them, three genes, namely chalcone synthase (CHS), glutathione S-transferase (GST) and malate dehydrogenase (MDH1) were present in both cultivated and wild grapes and peaches.

Development of fat-reduced 3D printed chocolate by substituting cocoa butter with water-in-oil emulsions

This study developed a fat-reduced 3D printed chocolate by substituting cocoa butter with gum Arabic based water-in-oil emulsions. A 3D printed chocolate formulation was firstly obtained by adjusting the ratios of powder sugar, cocoa butter, and cocoa powder. The formulations with optimal 3D printability possessed cocoa butter, icing sugar, and cocoa powder ratio of 2:1:2.5. Different levels of cocoa butter (25%, 50%, and 75%) were substituted using water-in-cocoa butter emulsions with different water/oil ratios (2:8, 3:7, 4:6, v/v) to obtain fat-reduced 3D printed chocolate. Results from differential scanning calorimetry and X-ray diffraction study suggested these fat-reduced chocolate still maintained the desired polymorphic form V of cocoa butter. Apparent viscosity study suggested that these chocolate formulations possessed shear-thinning behavior and the viscosity increased with addition of water phase. Texture profile analysis indicated that incorporation of high emulsion content increased the snap quality of these chocolate. Emulsion droplet structure was observed in optical images of fat-reduced chocolate formulations containing water-in-cocoa butter emulsions. Partially replacing 75% cocoa butter by emulsions with water/oil water ratio of 2:8 or 50% cocoa butter by emulsions with water/oil water ratio of 3:7 didn't affect the original printability of 3D printed chocolate. Overall, this study successfully developed a 3D printed fat-reduced chocolate by using gum Arabic based water-in-oil emulsions substitute, which possessed the potential to become functional chocolate for incorporation of both hydrophilic and lipophilic bioactives in the future.

Variation of Root Soluble Sugar and Starch Response to Drought Stress in Foxtail Millet

Foxtail millet is an important crop in Northwest China; however, the mechanism responsible for regulating root adjustment, including water uptake, sugar transport, or metabolism, in foxtail millet remains unclear. Two millet cultivars (the drought-resistant Yugu1 [YG] and the drought-sensitive An04 [An]) were used to detect physiological, molecular, and agronomic traits under two different soil water conditions. Water use efficiency increased by 18.4% and 63.2% under drought stress in An and YG, respectively. Under drought stress, YG and An root exudation (RE) decreased by 66.7% and 89.0%, the photosynthesis rate decreased by 34.3% and 61.8%, and the grain yield decreased by 40.6% and 62.6%, respectively. An contained a high ratio of soluble sugar to starch, whereas YG remained consistent. RNA-seq data showed a lower expression of beta-amylase 2 in YG than in An. The expression levels of three SWEET genes involved in sugar transport and four plasma membrane intrinsic protein (PIP) genes were higher in YG than in An, allocating more photosynthetic sugar to the roots to prevent a significant elevation in the ratio of soluble sugar to starch. The high expression levels of SiPIPs also enhanced root water transport capacity. Based on the above-mentioned adaptations, millet maintains high RE, stomatal conductance, and net photosynthetic rate in drought stress conditions.

Complementation between microbial necromass and plant debris governs the long-term build-up of the soil organic carbon pool in conservation agriculture

Plant residue is ultimately the source of soil organic matter but occurs as a continuum from relatively fresh plant tissue to highly evolved components. Nevertheless, the extent to which crop residue accumulates as plant tissue versus microbial necromass in conservation agricultural systems is still uncertain. A 12-year conservation tillage experiment with maize additions of zero, half and full harvest was conducted in Northeast China. Soil samples in the 0–10 cm depth were collected at 1–4 year intervals. The microbial residue biomarker amino sugar and plant component biomarker lignin phenol were quantified to trace the dynamics of microbial necromass and plant debris. Compared with the initial value, the content of amino sugar increased exponentially to 21–45% and approached steady-state equilibrium after 12 years of maize straw mulching, indicating the existence of “microbial carrying capacity” under repeated plant residue addition. With prolonged duration of conservation tillage and increasing rate of maize straw return, the ratio of amino sugar to lignin phenol decreased from 6.2 to 1.7, accompanied by a decreased degree of lignin side-chain oxidation, indicating that organic input enhanced the selective retention of fresh plant lignin to a larger extent than microbial necromass. The build-up of the SOC pool under conservation tillage was critically controlled by the functional complementation of microbial- and plant-derived components. Maize straw input was able to enhance the contribution of microbial necromass to SOC stabilization by increasing fungal necromass accumulation, while the retention of lignin-like plant debris enlarged the SOC pool capacity and potentially maintained the decomposability of SOC in the long term.