Cassava (Manihot esculenta Crantz) is continuously cultivated using the conventional tillage (CT) method in southern China, resulting in increasingly compact soil and decreased yield and fertilizer use efficiency (FUE) year after year. Compared to CT, Fenlong (FL) tillage, which uses spiral drill bits to replace traditional ploughshares, has been found to significantly increase crop yield ranged from 10% to 50% such as cassava, sugarcane, maize, cotton, rice, and wheat without extra fertilizer input. However, previous studies have primarily elucidated the mechanism behind yield increases from FL by examining changes in soil physicochemical properties and microbial communities. Research on how it enhances FUE remains scarce. Thus, the current study aimed to investigate how FL influences both cassava yield and FUE, which would be of great significance for implementing the plan “increasing crop yield without increasing fertilizer” released by the Ministry of Agriculture of China. Results indicated that the soil porosity of the FL treatment was 2.07 to 38.37% higher than that of the CT group. Moreover, compared with CT, the soil bulk density under FL treatment decreased by 0.64% to 12.07% across different soil layers, with significant reductions observed in the 11 ~ 30 cm layers in 2019 and the 21 ~ 30 cm layer in 2020. The relative abundance of aerobic bacteria (i.e., Gemmatimonadaceae [Family] and Tumebacillus [Genus] in 2019; Micromonosporaceae [Family], Tumebacillus [Genus], Conexibacter [Genus], and Acidobacteriales [Order] in 2020) in the FL group was higher than that in CT. The FL treatment significantly outperformed CT, with increases ranging from 9.04 to 135.81% in tuberous root yield, 11.51 to 62.07% in FUE-N, and 21.75 to 40.76% in FUE-K, while the fertilization regime of N 118.2 kg.ha−1, P2O5 29.4 kg.ha−1, and K2O 61.9 kg.ha−1 under FL managed to reach an ideal balance between cassava yield and FUE. Structural equation modeling revealed that FL tillage improves soil conditions for cassava and aerobic bacteria through deep soil fragmentation. This promotes soil fertility, facilitates deeper root penetration for enhanced nutrient and water uptake, and ultimately leads to higher yield and FUE compared to CT.

Cassava sustainable production in China is hindered by the persistent oversight of the continuous cropping obstacle (CCO), exacerbated by limited land resources. Based on a four-year experiment, this study examines the impact of cropping duration on plants and soil microbes. Continuous cropping beyond three years led to a yield decline, alongside intensified soil acidification and nutrient loss. This was accompanied by a decline in soil microbial diversity, with bacterial communities showing greater vulnerability than fungal communities. The irreversible degradation of the bulk soil microbial network was found as a key driver of CCO. Following four years of monocropping, Actinobacteriota (21.33

Drought and salt stress are two major abiotic factors significantly impacting crop growth and yield. Climate change leads to increasing drought and soil salinization issues, rising significant challenges to agricultural production. Amylases play a crucial role in enhancing the tolerance of crops to these stresses by regulating physiological and enzymatic activities. Previous study identified MeAMY1 and MeBAM3 as key genes involved in cassava starch metabolism under drought stress. To investigate their functions under drought and salt stress, MeAMY1 and MeBAM3 genes were cloned and over-expressed in Arabidopsis thaliana in the current study. Overexpression of MeAMY1 in Arabidopsis enhances amylase activities, promotes starch hydrolysis, releases soluble sugar and thus enhances osmotic balance in transgenic Arabidopsis. In the mean while, expression of BAM1 and SEX1 were depressed by MeAMY1 to maintain the protects cells closed under stress and preserved starch for adapting the stressful environments. Overexpression of the MeBAM3 in Arabidopsis can increase the expression levels of AMY3 and RVE1, promotes starch hydrolysis, releases soluble sugar from the chloroplasts to the cytoplasm and thus enhances osmoregulatory substance content, reducing stress-induced damage to antioxidant enzymes and cell membranes and improving stress tolerance. The principal component analysis further indicated that MeAMY1 and MeBAM3 overexpression lines responded similarly to drought stress, while MeBAM3 overexpression provided greater resilience to salt stress.

Cassava (Manihot esculenta Crantz) is cultivated for its starchy root and mainly used as starch and biofuel feedstock in China. The red spider mite (Tetranychus cinnabarinus Boisduval) is one of the main insect pests reducing cassava yields and becoming more and more serious with regard to the increasing continuous cropping years in China. The results indicated that SC205 (4×) was more resistant to T. cinnabarinus infestation than SC205 (2×) according to the leaf damage ingestion, nutrient substance and secondary metabolite results. The T. cinnabarinus infestation triggered the expression of many genes and various metabolic processes reaction. Under the mite feeding stress, SC205 (2×) and SC205 (4×) shared 4494 and 5849 differentially expressed genes (DEGs) at 2 and 8 days, respectively. The DEGs were found enriched in the defense pathways flavonoid biosynthesis (map00941) and the flavone and flavonol biosynthesis (map00944), while, differentially accumulated metabolites (DAMs) were also found enhanced in flavonol biosynthesis (map00944) and phenylpropanoid biosynthesis pathway (map00940). Integrative analysis revealed that under 8-day pest hazards, both DEGs and DAMs in SC205 (2×) and SC205 (4×) were significantly co-enriched in several key pathways, including alpha-linolenic acid metabolism, ABC transporters, galactose metabolism, ascorbate and aldarate metabolism, alanine, aspartate and glutamate metabolism, and tyrosine metabolism. These findings suggest that carbohydrate metabolism and amino acid metabolism play crucial roles in cassava’s resistance to T. cinnabarinus infection. Our study reveal the mechanisms of how cassava diploid and its autopolyploid in response to the feeding of T. cinnabarinus and provides data support for the precise analysis of cassava resistance and mite resistance breeding in further research.

As a starch and biofuel feedstock in China, cassava (Manihot esculenta Crantz) is continuously cultivated on marginal land in the south, predominantly in red and yellow soil types. With the prolonged application of conventional tillage (CT) method (mouldboard ploughing once at a depth of 30-35 cm and then raked twice at a depth of 18 cm), the soil became increasingly compact, while the cassava yield decreased year after year. The previous study reported that the cassava yield was significantly increased by Fenlong (FL) tillage, which implements the use of spiral drill bits to replace traditional ploughshares. Thus, the current study aimed to reveal how FL combined with N application affects the bacterial community diversity of cassava rhizosphere soil. The results indicated that Actinobacteria, Proteobacteria, Chloroflexi, Acidobacteria, and Firmicutes were the most abundant phyla in cassava rhizosphere soil. The relative abundances of Actinobacteria, Firmicutes, and Gemmatimonadetes of the CT group were generally higher than the FL group in 2019, while the relative abundances of Actinobacteria, Chloroflexi, and Planctomycetota in the FL treatments were higher than those in the CT treatments in 2020. In addition, the abundance of the phylum Acidobacteria decreased with the N application rate, and its abundance was generally higher in the FL group than in the CT group in 2019. Genera norank_o__Gaiellales, Bryobacter, Pseudolabrys, Acidothermus, Rhodoplanes, Conexibacter, and Paenibacillus were also found higher enriched in the FL treatment than in the CT treatment. These results indicate that FL tillage exhibited stronger abilities than CT for recruiting host-specific bacteria of cassava by creating better conditions for roots and thus boosting more exudates based on the developed root system.

For revealing the mechanism of cassava continuous cropping obstacle formation,we study planted cassava in a fixed field for three continous years,and applied high-throughput sequencing technology and bioinformatics to explore effects of continuous cropping on fungal community structure of both rhizosphere and non-rhizosphere soils of cassava.The results were as follows:(1)Continuous cropping caused significant effects on the α diversity and β diversity of rhizosphere and non-rhizosphere soil fungal communities of cassava.(2)The dominant fungi phyla of cassava rhizosphere and non-rhizosphere soils were Ascomycota,SAR_k_norank,Basidiomycota,Mucoromycota,and unclassified_k_Fungi,and the main classes were Sordariomycetes,Eurotiomycetes,and Dothideomycetes.The composition of Ascomycota of the non-rhizosphere soil varied with the continuous cropping years significantly and the Myrothecium,Sordariomycetes,and Dothideomycetes evolved to single genus Knufia in the first year.In the rhizosphere soil,Hypocreales,Chaetothyriales,Myrothecium,Dothideomycetes,and Sordariomycetes evolved to Monosiga,Choanoflagellida.(3)Soil pH,organic matter content,available nitrogen content,available phosphorus content,available potassium content,and urease activity significantly influenced the structure of fungal communities,especially for distributions of Ascomycota,SAR_k_norank,Basidiomycota,and Mucoromycota.In conclusion,continuous cropping of cassava influenced soil physicochemical properties through the accumulation of root exudates,thus altering the survival environment of fungi,leading to differences of the diversity and the abundance of fungal communities between cassava rhizosphere and non-rhizosphere soils.The ascomycetes in the non-rhizosphere soil evolved from Myrothecium,Sordariomycetes,and Dothideomycetes to single genus Knufia.The relative abundance of Hypocreales,Myrothecium,and Sordariomycetes of Ascomycota decreased with continuous cropping years in the rhizosphere soil,which may be one of main causes of the continuous cropping obstacles of cassava.

[目的]鉴定木薯根系分泌物中的主要自毒物质,为系统研究木薯连作障碍机制及其缓解措施提供理论依据.[方法]以广西主栽木薯品种华南205(SC205)为试验材料,利用其组培苗模拟连作栽培,采用气相色谱—质谱联用仪(GC-MS)和生物测定方法检测其根系分泌物中的主要自毒物质,明确其化感效应.[结果]模拟连作1茬和2茬木薯组培苗的株高、地上部和地下部鲜重均显著低于模拟连作0茬木薯组培苗(P＜0.05),其综合化感效应均为负值,且连作2茬木薯组培苗对株高、地上部和地下部鲜重的抑制作用大于连作1茬.从连作木薯组培苗根系分泌物中鉴定出78种化学物质,经GC-MS定量检测发现含量较高的为羟基丙酮、乙酸和2,4-二叔丁基苯酚.与连作0茬相比,连作1茬和2茬木薯组培苗根系分泌物中的乙酸含量分别增加32.40％和16.49％,2,4-二叔丁基苯酚含量分别减少52.27％和85.15％;连作1茬木薯组培苗的羟基丙酮含量增加38.11％,连作2茬木薯组培苗的羟基丙酮含量减少29.03％.生长试验结果表明,2,4-二叔丁基苯酚是对木薯组培苗生长抑制作用最强的自毒物质;羟基丙酮对木薯组培苗生长的抑制作用以高浓度(1 ×10-3mol/L)处理大于低浓度(1 ×10-5mol/L)处理;乙酸低浓度(1 ×10-5 mol/L)处理可抑制木薯组培苗生长,但高浓度(1 ×10-3 mol/L)乙酸对木薯组培苗生长具有一定的促进作用.[结论]连作木薯组培苗根系可分泌至少78种化学物质,其种类和含量均随着组培苗连作茬数的增加而变化,其中的2,4-二叔丁基苯酚和羟基丙酮属于抑制木薯组培苗生长的重要自毒物质,生产上应采取相应措施减少其产生或缓解其在木薯根系中的累积.

Background Starch hydrolysates are energy sources for plant growth and development, regulate osmotic pressure and transmit signals in response to both biological and abiotic stresses. The α-amylase (AMY) and the β-amylase (BAM) are important enzymes that catalyze the hydrolysis of plant starch. Cassava ( Manihot esculenta Crantz) is treated as one of the most drought-tolerant crops. However, the mechanisms of how AMY and BAM respond to drought in cassava are still unknown. Results Six MeAMY genes and ten MeBAM genes were identified and characterized in the cassava genome. Both MeAMY and MeBAM gene families contain four genes with alternative splicing. Tandem and fragment replications play important roles in the amplification of MeAMY and MeBAM genes. Both MeBAM5 and MeBAM10 have a BZR1/BES1 domain at the N-terminus, which may have transcription factor functions. The promoter regions of MeAMY and MeBAM genes contain a large number of cis-acting elements related to abiotic stress. MeAMY1 , MeAMY2 , MeAMY5 , and MeBAM3 are proven as critical genes in response to drought stress according to their expression patterns under drought. The starch content, soluble sugar content, and amylase activity were significantly altered in cassava under different levels of drought stress. Conclusions These results provide fundamental knowledge for not only further exploring the starch metabolism functions of cassava under drought stress but also offering new perspectives for understanding the mechanism of how cassava survives and develops under drought.

Cassava (Manihot esculenta Crantz) is mainly cultivated in marginal land in the south of China where seasonal drought stress occurs frequently and the soil becomes more compact year by year. The study aimed to explore the effect of Fenlong tillage (FLT) combined with nitrogen applications on cassava rhizosphere soil particle composition and fungal community diversity. Conventional tillage (CT) was set as the control. The results indicated that the contents of clay and silt of the cassava rhizosphere soil were influenced by the tillage method, nitrogen (N), and their interaction. There was no difference in the richness and diversity of rhizosphere soil fungal communities among all treatments in 2019, while the richness of FLT was lower than that of CT in 2020. FLT caused a stronger influence on the community structure of rhizosphere fungi than N applications in the first year. The differences in the community structure of all treatments were reduced by continuous cropping of cassava in the second year. The top 10 dominant rhizosphere fungi at the class level of cassava found in 2019 and 2020 were Sordariomycetes, Dothideomycetes, Eurotiomycetes, Agaricomycetes, Intramacronucleata, norank_p__Mucoromycota, unclassified_p__Ascomycota, unclassified_k__Fungi, Pezizomycetes, and Glomeromycetes, which had an important relationship with soil pH, activity of urease, available nitrogen, available phosphorus, organic matter, and clay. These results indicated that FLT created a better soil environment for cassava growth than CT, thus promoting the formation of more stable rhizosphere fungal community structures.

Cassava stems contain up to 40% starch (by dry mass) and are currently discarded as agricultural waste. The current study aims to understand the physicochemical traits of cassava stem and root starches for investigating trends in industrial cassava applications. In total, 11 traits of both cassava stem and root starches of 15 genotypes are investigated. All the examined traits of cassava root and stem starches vary by genotype. The amylose contents of root and stem starches are in the range of 19.0-33.0% and 18.44-34.51%, respectively. The resistant starch of root and stem starches are in the range of 1.72-17.72% and 4.42-13.37%, respectively. Only the starch content, solubility, and swelling power of root starches are significantly higher than those of stem starches. The root starch gel is more stable than the stem starch gel after the fourth and fifth freeze-thaw cycles. Furthermore, principal component analysis calculated based on starch and amylose contents, degree of swelling, digestibility, and freeze-thaw stability demonstrates that genotypes GW46, GW88, S1, E26, and GC49 gain higher scores than control varieties South China 12 and South China 205, which are the most favorable ones by farmers in China because of good root yields.

本研究通过对木薯根系分泌物进行提取、分离与鉴定,探究不同木薯品种根系分泌物的差异,为筛选抗化感耐连作木薯新种质提供参考.以木薯组培苗琼脂培养基为试验材料,采用正交试验设计,结合GC-MS技术考察不同萃取材料和洗脱剂对木薯根系分泌物的提取和分离效果,选择最优方案测定'新选048'南植199'和'华南205'的根系分泌物.结果表明:(1)木薯根系分泌物水溶性物质提取的最优方案为:用去离子水超声提取捣碎的琼脂培养基30 min,固液分离后用XAD-2萃取、无水乙醇洗脱,浓缩后用GC-MS检测,成功鉴定出包括有机酸类、醇类、酯类、酮类、醛类等26种有机化合物.(2)醇溶性物质提取的最优方案为:用50％乙醇超声提取捣碎的琼脂培养基30 min,固液分离后用XAD-4萃取、无水乙醇洗脱,浓缩后用GC-MS检测,鉴定出包括有机酸类、醚类、酯类、酮类、醛类等15种有机化合物.(3)不同品种根系分泌物的水溶性和醇溶性成分均有差异.'南植199'根系分泌物的主要水溶性物质有羟乙酸甲酯(相对含量为3.72％)、羟基丙酮(2.40％)、甲肼(1.79％)等,主要醇溶性物质有乙醇醛(18.89％)、羟基丙酮(2.47％)、甲酸(2.25％)等;'新选048'的主要水溶性物质有甲酸(2.68％)、1,5-戊二醇(2.39％)、丙烯酸羟乙酯(2.01％)等,主要醇溶性物质有乙醇醛(17.00％)、甲酸(2.62％)、羟基丙酮(2.46％)等;'华南205'的主要水溶性物质有甲酸(2.23％)、羟基丙酮(1.80％)、羟乙酸甲酯(1.43％)等,主要醇溶性物质有乙醇醛(16.58％)、甲酸(3.06％)、八氟戊醇(2.98％)等.不同木薯品种的根系分泌物种类和含量均有差异,从而导致其抗化感耐连作能力的差异,为筛选耐连作品种缓解木薯连作障碍成为可能.

[目的]分析粉垄耕作下的木薯根际和非根际土壤理化性质及细菌群落多样性差异,为优化现有木薯栽培方法提供理论依据.[方法]以常规耕作和粉垄耕作2种耕作方式栽培木薯,利用高通量测序技术和生物信息学手段,结合土壤农化分析方法,分析不同耕作方式对木薯根际与非根际土壤理化性质及主要优势细菌群落结构多样性的影响.[结果]木薯根际土壤细菌群落的Alpha(α)多样性显著高于非根际土壤(P＜0.05,下同).基于未加权Unifrac距离的置换多因素方差分析(PERMANOVA)结果显示,木薯根际土壤与非根际土壤细菌群落的分类和系统发育Beta(β)多样性存在显著差异.物种群落组成分析结果表明,木薯根际土壤的主要优势菌门为放线菌门、变形菌门、绿弯菌门、厚壁菌门和酸杆菌门,主要优势菌纲为α-变形菌纲、放线菌纲、芽孢杆菌纲和γ-变形菌纲.在分类操作单元(OTU)水平,粉垄耕作与常规耕作方式木薯根际与非根际的土壤细菌群落组成存在显著差异.细菌群落相对丰度与环境因子的相关分析和冗余分析(RDA)结果显示,pH、有机质含量、有效磷含量和亚硝酸还原酶活性对细菌群落变化具有显著影响,尤其对放线菌门、变形菌门、绿弯菌门、厚壁菌门和酸杆菌门分布的影响更明显.[结论]木薯粉垄耕作方式通过改善土壤耕作层的物理结构而减少木薯逆境胁迫,使得其根际土壤pH及有机质、有效磷和速效钾含量大于非根际土壤,进而引起根际土壤细菌群落多样性和丰富度均大于非根际土壤,其中根际土壤细菌群落α多样性显著高于非根际土壤.木薯根际土壤与非根际土壤细菌群落多样性的差异主要体现在根际土壤中芽孢杆菌属、芽单胞菌属、Ellin6067属和马赛菌属的丰度显著高于非根际土壤.

[目的]研究粉垄耕作与氮肥减施对木薯地土壤温室气体排放及土壤酶活性的影响,明确粉垄栽培木薯的增产及碳减排效应,为木薯种植业的可持续发展提供技术支撑.[方法]以木薯品种华南205为试验材料,利用粉垄耕作和常规耕作2种方式进行整地,分别设4个不同施氮量水平(100％N、50％N、25％N和0N),分2次追肥,于第1次追肥后至木薯收获期采集土壤温室气体及土壤样品,研究耕作方式及施氮量对土壤脲酶、过氧化氢酶活性及土壤温室气体排放量、净增温潜势(GWP)、温室气体强度(GHGI)和固碳量的影响.[结果]在木薯整个生育期中,2种耕作方式下,100％N处理的土壤脲酶活性较高,25％N处理的土壤过氧化氢酶活性较高,且粉垄耕作的酶活性整体上高于常规耕作.土壤温室气体累积排放量、GWP、GHGI和土壤固碳量均受耕作方式和施氮量的双重影响.减氮处理有利于降低土壤N2O、CH4和CO2的累积排放量及GWP和GHGI,0N处理的土壤温室气体排放量均最低;常规耕作100％N处理的土壤GWP和GHGI分别为1170.4 kg/ha和0.069 kg/kg,均显著高于各减氮处理(P<0.05,下同);粉垄耕作100％N处理的GWP和GHGI分别为367.6 kg/ha和0.014 kg/kg,与各减氮处理差异不显著(P>0.05).相同施氮量处理下,粉垄耕作的土壤固碳量均显著高于常规耕作,其中100％N处理的土壤固碳量最高,为1.95 kg/(ha·a).[结论]粉垄耕作可通过优化土壤理化性质,提高土壤固氮效率,改善土壤固碳能力.在相同的试验条件下,粉垄耕作100N％处理的碳减排效果最明显.

This study compared the effects of hot-air pasteurisation (HAP) at 75-100 degrees C versus autoclaving at 121 degrees C and 2 bar overpressure on the lignocellulosic degradation process of birch-based substrates that were used for shiitake mushroom cultivation and potential bioethanol production. Fifty substrate samples were obtained as a time series from different stages of the cultivation, and their chemical contents were measured by chemical analysis and near infra-red spectroscopy (NIR). Despite of different energy intensities, HAP and autoclaving did not result in significant differences in the degradation of lignin and carbohydrates. Major compositional changes were associated with the cultivation process. Principal component analysis on the wet chemical data and orthogonal projections to latent structures based on NIR spectra reached the same conclusion, namely that HAP had similar effect as autoclaving on compositional changes in the substrate during cultivation. The results of this study suggest that a substitution of autoclaving by HAP may potentially save up to 9.9 TWh energy for the global production of 7.5 million ton shiitake. At the same time, lignocellulose feedstock can be pretreated for the production of up to 3.24 million m(3) of 95%-ethanol fuels, which can potentially substitute proximate 1.88 million m(3) of regular gasoline. (C) 2020 Elsevier Ltd. All rights reserved.

Sucrose phosphate synthase (SPS), a key rate-limiting enzyme in the sucrose biosynthesis pathway in plants, is encoded by a multi-gene family. Until recently, the identification and characterization of the SPS gene family have been performed for dozens of plant species; however, few studies have involved a comprehensive analysis of the SPS family members in tropical crops, such as cassava (Manihot esculenta Crantz). In the current study, five SPS genes (MeSPS1, MeSPS2, MeSPS3, MeSPS4, and MeSPS5) were isolated from cassava, and their sequence characteristics were comprehensively characterized. These MeSPS genes were found distributed on five chromosomes (Chr2, Chr14, Chr15, Chr16, and Chr18). Phylogenetic analysis showed that the MeSPS protein sequences were clustered into three families, together with other SPS sequences from both dicot and monocot species (families A, B, and C). The spatio-temporal expression pattern analysis of MeSPS genes showed a tissue-specific and partially overlapping expression pattern, with the genes mainly expressed in source tissues during cassava growth and development. Correlation analysis revealed that the expression of MeSPS genes correlated positively with root starch content, indicating that the expression of MeSPS genes might accelerate the rate of starch accumulation in the roots of cassava plants.

The objective of this study was to explore the physiological and molecular mechanisms of a drought-tolerant cultivar (Xinxuan048, XX048) and a drought-sensitive cultivar (Kasetsart 50, KU50) at four growth phases under drought stress. Treatments were composed of three drought stress levels, viz., keeping the soil moisture content as 55–60%, 35–40%, and 15–20% of field capacity last for 15 days, respectively. Results showed that cassava growth and yield were substantially decreased with increasing drought stress. Oxidative damage enhanced with the increasing drought stress in both cassava cultivars. Compared with KU50 cultivar, XX048 showed stronger activation of the antioxidant defense system at different growth stages. This resistance to oxidative stress in XX048 was the result of increased accumulation of ascorbic acid (AsA) content and higher peroxidase (POD) and catalase (CAT) activities under drought stress. Furthermore, RNA-Seq data revealed that six drought-induced differentially expressed genes associated with antioxidant defense were also observed. qRT-PCR analysis showed that the relative expression levels of these genes were higher in XX048 compared with KU50. Conclusively, the XX048 cultivar was more beneficial in terms of high yield and drought tolerance due to more AsA content and higher POD and CAT activities and genes expression at different growth stages under water stress compared with KU50 cultivar. These data could provide fundamental knowledge for improving the approaches of cassava cultivation and molecular breeding with drought-resistant features.

Cassava stems are an abundant feedstock that is becoming attractive for biochemical conversion to fuels and chemicals. Since cassava stems are rich in both cellulose and starch, carefully designed pretreatment and digestion procedures are required for achieving high glucan recovery. In this study, partially de-starched cassava stems resulting from a water extraction stage were hydrolyzed with amylases, and the resulting starch-depleted material was pretreated with dilute sulfuric acid, and submitted to enzymatic hydrolysis of cellulose. The effects of acid pretreatment on glucan recovery, enzymatic convertibility, and by-product formation were investigated using a Box-Behnken experimental design with temperature (165-195 degrees C), time (5-35 min), and acid concentration (0.2-1.0%) as independent variables. In further experimental series, the time period was extended up to 110 min while maintaining temperature at 195 degrees C and sulfuric acid concentration at 0.6%. Using those conditions, pretreatment for 50 min gave the best results (83.8% enzymatic convertibility of pretreated cellulose, and (similar to)72% overall glucan-to-glucose conversion).

Drought stress is one of the potent abiotic stress limiting cassava (Manihot esculenta) yield globally, but studies addressing both physiological and proteomic responses that how cassava crops can adjust their growth and metabolism under drought conditions are lacking. Combining leaf physiological and proteomic characteristics strongly allied with drought tolerance should results in enhanced drought tolerance in cassava crop. Therefore, the aims of this study were to explore the plant physiological and proteomic mechanisms involved in drought adaptation in cassava. Xinxuan 048 (XX048) was exposed to well-watered control (CK, relative soil water content (RSWC) as 80 ± 5%), mild drought stress (LD, RSWC as 65 ± 5%), moderate drought stress (MD, RSWC as 50 ± 5%) and severe drought stress (SD, RSWC as 35 ± 5%) from 30 days after planting. Under drought stress conditions, cassava plant showed a substantial decline in plant height, stem diameter, leaf number, leaf water content, the ratio of free water content to bound water content of leaf (FW/BW), net photosynthetic rate (Pn), intercellular CO2 concentration (Ci), stomatal conductance (Gs) and transpiration rate (Tr) compared with well watered plants. However, compared with control, leaf water content, SPAD value, cell membrane permeability, malondialdehyde (MDA), soluble sugar, protein proline content SOD and CAT activity were at peak under drought stress. The proteomic analysis revealed that among 3 339 identified proteins, drought stress increased and decreased abundance of 262 and 296 proteins, respectively, compared with control condition. These proteins were involved in carbohydrate energy metabolism, protein homeostasis, transcription, cell structure, cell membrane transport, signal transduction, stress and defense responses. These data not only provides a comprehensive dataset on overall proteomic changes in cassava leaves under drought stress, but also highlights the mechanisms by which euphorbiaceae plants can adapt to drought conditions.

Hot-air (75-100 degrees C) pasteurisation (HAP) of birch-wood-based substrate was compared to conventional autoclaving (steam at 121 degrees C) with regard to shiitake growth and yield, chemical composition of heat-pretreated material and spent mushroom substrate (SMS), enzymatic digestibility of glucan in SMS, and theoretical bioethanol yield. Compared to autoclaving, HAP resulted in faster mycelial growth, earlier fructification, and higher or comparable fruit-body yield. The heat pretreatment methods did not differ regarding the fractions of carbohydrate and lignin in pretreated material and SMS, but HAP typically resulted in lower fractions of extractives. Shiitake cultivation, which reduced the mass fraction of lignin to less than half of the initial without having any major impact on the mass fraction of glucan, enhanced enzymatic hydrolysis of glucan about four-fold. The choice of heating method did not affect enzymatic digestibility. Thus, HAP could substitute autoclaving and facilitate combined shiitake mushroom and bioethanol production.

This study aims to understand the starch properties of cassava stems, currently a discarded crop residue, which contain up to 40% starch by dry mass. Granule sizes and size distribution of cassava stem starch, and their variations with genotype, growing location, and position along the stem are investigated using scanning electron microscopy (SEM) images. Amylose contents, crystallinity, and pasting characteristics of stem and root starch are also compared. The mean of granule sizes range from 5.65 to 7.64 µm, depending on the environment and position along stems, but not on genotype. Stem starch has a similar granule shape, X‐ray diffraction pattern, and amylose content (20.8% of starch basis) to root starch, but a significantly smaller granule size with narrower distribution range and higher pasting temperature (72.1 °C). Cassava stem has a woody nature; a development of an efficient starch isolation method shall be included in future studies.