Starch Grains Research Articles

Characterization of Starch Physicochemical Properties and Grain Transcriptome Reveal the Mechanism for Resistant Starch Accumulation

Understanding the physicochemical properties of starch during grain development and the mechanism for resistant starch (RS) accumulation will provide useful information for improving the RS content of wheat. The grains from wheat mutant lines with high RS contents and their corresponding wild-type control were analyzed to characterize the structural and physicochemical properties of wheat starch. A transcriptomic analysis was used to analyze the differentially expressed genes (DEGs) involved in RS accumulation. The results showed that the RS content increased with grain development, along with the total starch content, but a larger increase was observed in the middle and later stages of grain filling. The X-ray diffraction peak intensity and relative crystallinity of starch exhibited the lowest and highest values at 10 days after anthesis, respectively. Regarding the thermal properties of starch, the peak temperature and conclusion temperature generally decreased with grain development; however, the enthalpy values showed no apparent regularity. Compared to control cultivar ZM22, the RS639 and RS683 lines with high RS contents showed high amylose contents and high relative crystallinity and a large proportion of 2.0~9.8 µm starch granules. Furthermore, the transcriptomics analysis revealed that the average relative expression of the glucan-branching enzyme (GBE) α-1,4 glucan phosphorylase (Pho) and starch synthase (SS) in ZM22 was 2.47-, 2.70-, and 2.56-fold higher than that in RS639, respectively; which indicates that the downregulation of the expression of genes encoding GBE, Pho, and SS in wheat grain promotes the accumulation of RS.

Characterization of two peanut genotypes for biochemical quality attributes and cotyledon microstructure features

Peanut is a world-renowned oilseed and food crop. Improving its biochemical quality is of great significance not only for meeting the demand for edible oil and food, but also for producing clean renewable energy. Identification of peanut genotypes with high and stable oil content in coastal areas is of economic importance, as the high oil trait of peanut bred in inland areas is difficult to fully express in coastal areas. Two peanut genotypes were grown at two sites in the coastal area. One of the genotypes was identified as having high oil and low carbohydrate, while the other had low oil and high carbohydrate. We noticed that number and total area of oil bodies were higher in high oil peanut than in low oil peanut, and that peanut with higher protein content had larger total protein body area. A novel finding of the present study was that number and area of starch grains were higher in peanut with high total soluble sugar (TSS) and sucrose contents than in peanut with low TSS and sucrose. Regarding the ultrastructural properties associated with oil, protein and TSS/sucrose contents, significant and highly positive correlations were detected between total oil body area and number of oil bodies, between total protein area and maximum protein body area, and between total starch grain area and number of starch grains. This study laid the foundation for further exploration of the mechanisms shaping peanut seed biochemical quality.

Physiological responses to pH in the freshwater microalga Limnomonas gaiensis.

The ecological niche of the recently described limnic microalga Limnomonas gaiensis (Chlamydomonadales) in Northern Europe remains unknown. To decipher the species tolerance capacity to pH, the effects of hydrogen ions on the physiological response of L. gaiensis were investigated. Results showed that L. gaiensis could tolerate exposure from pH 3 up to pH 11, with an optimal survival at pH 5-8. Its physiological response to pH was strain specific. Globally the southernmost strain was more alkaliphilic, had a slightly rounder shape, a slowest growth rate, and a lowest carrying capacity. Despite strain discrepancies among lakes, Swedish strains exhibited similar growth rates, faster at more acidic conditions. The extreme pH conditions affected its morphological features such as the eye spot and papilla shape, especially at acidic pH, and the cell wall integrity, at more alkaline pH. The wide range tolerance of L. gaiensis to pH would not be a hindrance to its dispersal in Swedish lakes (pH 4-8). Notably, the storage of high-energetic reserves over a wide range of pH conditions, as numerous starch grains and oil droplets, makes L. gaiensis a good candidate for bioethanol/fuel industrial production and a key resource to sustain aquatic food chain and microbial loop.

Comparative morpho-anatomical study on Leptadenia pyrotechnica (Apocynaceae) growing in the hyper-arid and arid habitats of Saudi Arabia.

The use of wild plants is considered to be an eco-friendly and promising natural resource. In sandy desert habitats, Leptadenia pyrotechnica flourishes as a xerophytic shrub with high biomass production. As a dominant shrub in the arid sand dune habitats of Saudi Arabia, Leptadenia pyrotechnica (Forssk.) Decne (Asclepiadaceae) is one of the most common xerophytes; the many medicinal uses of this plant include treating allergies, productive coughs, abortions, diabetes, stomach disorders, fevers, kidney disorders, and stones. In such a distribution, morpho-anatomical characteristics, among other adaptive traits, play an important role. This study aims to characterize some morpho-anatomical adaptations of L. pyrotechnica in two stressful habitats: the hyper-arid inland sand dunes of the Empty Quarter (EQ) and the arid coastal sand dunes of Jazan. A morpho-anatomical analysis of plant stems and roots from both habitats was conducted using light microscopy (LM) and scanning electron microscopy (SEM). The outcomes indicated similar characteristics, a low surface-to-volume ratio (S/V), a thin boundary layer (δbl), an epidermis with many layers of hypodermis, bundles of sclerenchymatous cells around vascular tissue, and storage starch grains in ray parenchyma between xylem conduits. On the other hand, the L. pyrotechnica stem from the hyper-arid habitat of the Empty Quarter revealed more encrypted stomata, more elongated palisade cells, less calcium oxalate crystals with low Ca percentage, and a high vulnerability index of xylem vessels compared with the same traits of the stem from the Jazan coastal sand dunes habitat. Roots of L. pyrotechnica from both habitats revealed similar features of general anatomy. However, differences in specific anatomical traits were observed, especially in xylem vessel characters. The vulnerability index of root xylem vessels from the Empty Quarter habitat was more than that from the Jazan coastal sand dunes habitat. Furthermore, vestured bordered pits in root xylem walls were more abundant in the Empty Quarter habitat than in the Jazan coastal sand dunes habitat. As a result, these characteristics in the morpho-anatomy of L. pyrotechnica from both habitats provide practical adaptations to highly stressful conditions, along with specific anatomical traits relating to each habitat.

Pharmacognostic profiles, evaluation of analgesic, anti-inflammatory and anticonvulsant activities of Newbouldia laevis (P. Beauv.) Seem. ex Bureau leaf and root extracts in Wistar rats

Ethnopharmacological relevanceNewbouldia laevis is a popular medicinal plant whose leaves and roots are used in Nigeria as ethnomedicinal prescriptions for pain, inflammation, convulsion, and epilepsy. These claims have not been scientifically verified prior to this study. Aim of the studyTo determine pharmacognostic profiles of the leaves and roots and evaluate the analgesic, anti-inflammatory, and anticonvulsant activities of methanol leaf and root extracts in Wistar rats. Material and methodsThe pharmacognostic profiles of the leaves and roots were determined using standard procedures to serve as fingerprints for the plant. The methanol leaf and root extracts of Newbouldia laevis were tested for acute toxicity using the OECD’s up and down method at the maximum dose of 2000 mg/kg (orally) in Wistar rats. Analgesic studies were carried out in acetic acid-induced writhing in rats and tail immersion. The anti-inflammatory activity of the extracts was evaluated using carrageenan-induced rat paw-oedema and formalin-induced inflammation in rats’ mode. The anticonvulsant activity was determined using strychnine-induced, pentylenetetrazol-induced, and maximal electroshock-induced rat convulsion models. For each of these studies, the extracts doses of 100, 200 and 400 mg/kg were administered to the rats following the oral route. ResultsThe pharmacognostic profiles showed that the leaves possessed deep-sunken paracytic stomata (5-8-16 mm2; adaxial, 8-11-24 mm2; abaxial epidermis), vein islets (2-4-10 mm2; adaxial), vein terminations (10-14-18 mm2; adaxial), palisade ratio (8.3-12.5-16.4 mm2; adaxial, 2.5-6.8-12.2 mm2; adaxial), covering unicellular trichome (8–14; adaxial), spheroidal calcium oxalate crystals (3–5 μm), and oval-shaped striated starch grain with no hilum (0.5–4.3 μm). The transverse section of the leaf showed the presence of spongy and palisade parenchyma as well as a closed vascular bundle. The root powder showed the presence of brachy sclereid, fibers without lumen, and lignin. All physicochemical parameters fall within the acceptable limits, phytochemical contents showed mainly glycosides, alkaloids, and steroids while acute oral toxicity (LD50) of the parts for 14 days did not produce any toxicity signs or mortality in the rats. The extracts produced dose-dependent (100–400 mg/kg) analgesic involving opioid receptors, anti-inflammatory, and anticonvulsant activities in the rats which were significant (p ≤ 0.05) when compared to the standard drugs. The leaf extract possessed the most potent analgesic and anti-inflammatory effects in the rats, while the most anticonvulsant effects were observed in rats treated with the leaf extract. Both extracts showed elevated levels of protection against strychnine-induced, pentylenetetrazol-induced, and maximal electroshock-induced seizure in rats. ConclusionOur study revealed some pharmacognostic profiles of Newbouldia laevis leaves and roots that are vital for its identification from closely related species often used for adulteration in traditional medicine. The study further showed that the leaf and root extracts of the plant possessed dose-dependent analgesics, anti-inflammatory and anti-convulsant activities in rats, thus, justifying its use for the treatment of these diseases in Nigerian traditional medicine. There is a need to further study its mechanisms of action towards drug discovery.

Designing a gingerbread product based on gluten-free vegetable compositions

The research is devoted to the creation of a new recipe and technological solutions for the production of gluten-free gingerbread products for people who need dietary nutrition. Our studies were carried out in accordance with GOST 15810-2014 «Confectionery products. Gingerbread products. General specifications». Based on marketing research, it has been established that nowadays production of gluten-free confectionery products, including gingerbread ones, is underdeveloped in the region. The following samples of gingerbread products are considered in the research: the control one – 100% wheat flour; No. 1 – 50% rice and 50% corn flour; No. 2 – 50% corn and 50% pumpkin flour. As a result of the experiments, sample No. 1 with the best organoleptic characteristics has been selected. The gluten level in the gingerbread product under study was calculated, and it amounted to 7 mg/kg, which according to TR CU 027/2012 was lower than the normalized value (20 mg/kg). Therefore, this product belongs to the «gluten free» product group. It has been established that due to the high water absorption capacity, the introduction of mixture No. 1 into the food industry is relevant, since there is a greater rise in the dough during baking and less thickening of starch grains. As a result of our calculations of the chemical composition of this product, it has been found that through the use of an alternative type of raw material, it is possible to design products with various contents of food and biologically active substances, including a vitamin–mineral complex, which are not inferior in their characteristics to traditional products made from wheat flour. Thus, the studies conducted have shown that the use of non-traditional types of raw materials (rice and corn flour) allows one to make gluten-free products with high quality indicators, including organoleptic, structural-mechanical properties and enriched in nutritional value.

A New SNP in AGPL2, Associated with Floury Endosperm in Rice, Is Identified Using a Modified MutMap Method

The floury endosperm mutants of rice can not only be used to uncover the molecular mechanisms involved in regulating starch synthesis and grain development but are also suitable for dry milling to produce rice flour of good quality. In this study, we identified and characterized a rice floury endosperm mutant, M10, from a mutant pool induced by EMS. The total starch content in the M10 seeds significantly decreased, while the soluble sugar content demonstrably increased. The grain hardness of M10 was lower than that of the wild type because of the spherical and loosely packed starch granules. The modified MutMap analysis demonstrated that AGPL2 on chromosome 1 is most likely to be the candidate gene causing a floury endosperm. The genome sequences of AGPL2 in M10 carried a single nucleotide substitution of guanine (G) to adenine (A) in the seventh exon, leading to a missense mutation from glycine (Gly) to glutamic acid (Glu) at the 251st amino acid. Allele test confirmed that AGPL2 is the gene responsible for the M10 phenotype. Both transcriptional and protein levels of AGPL2 in M10 were obviously higher than those in the developing endosperm of wild type, indicating a positive feedback regulation is caused by AGPL2 mutation. Together, our results suggest that AGPL2 plays a critical role in starch synthesis and that the modified MutMap method is feasible for identifying floury endosperm mutant genes in rice.

Wheat NAC-A18 regulates grain starch and storage proteins synthesis and affects grain weight.

Wheat NAC-A18 regulates both starch and storage protein synthesis in the grain, and a haplotype with positive effects on grain weight showed increased frequency during wheat breeding in China. Starch and seed storage protein (SSP) directly affect the processing quality of wheat grain. The synthesis of starch and SSP are also regulated at the transcriptional level. However, only a few starch and SSP regulators have been identified in wheat. In this study, we discovered a NAC transcription factor, designated as NAC-A18, which acts as a regulator of both starch and SSP synthesis. NAC-A18, is predominately expressed in wheat developing grains, encodes a transcription factor localized in the nucleus, with both activation and repression domains. Ectopic expression of wheat NAC-A18 in rice significantly decreased starch accumulation and increased SSP accumulation and grain size and weight. Dual-luciferase reporter assays indicated that NAC-A18 could reduce the expression of TaGBSSI-A1 and TaGBSSI-A2, and enhance the expression of TaLMW-D6 and TaLMW-D1. A yeast one hybrid assay demonstrated that NAC-A18 bound directly to the cis-element "ACGCAA" in the promoters of TaLMW-D6 and TaLMW-D1. Further analysis indicated that two haplotypes were formed at NAC-A18, and that NAC-A18_h1 was a favorable haplotype correlated with higher thousand grain weight. Based on limited population data, NAC-A18_h1 underwent positive selection during Chinese wheat breeding. Our study demonstrates that wheat NAC-A18 regulates starch and SSP accumulation and grain size. A molecular marker was developed for the favorable allele for breeding applications.

Structural Variation Patterns in Xylem Vessels and Parenchyma Cells and Their Association with Tree Evolution

Xylem vessels and parenchyma cells perform functions such as water transport and nutrient storage in trees. However, they are highly variable in different trees. Therefore, this study aimed to explore the structural change patterns in vessels and parenchyma cells in the sapwood, transition wood, and heartwood of tree species with different degrees of evolution. The structural characteristics of the two types of cells in the sapwood, transitional wood, and heartwood were measured in six species with different levels of evolution, namely, Michelia macclurei Dandy, Cinnamomum camphora (L.) presl, Erythrophleum fordii Oliv, Melaleuca leucadendron L., Parashorea chinensis Wang Hsie and Tectona grandis L.F. The results showed that the more evolved species had larger earlywood vessel lumen diameters, thicker walls, and wider hydraulic diameters, as well as smaller latewood vessel densities, reflecting better water transport effectiveness and higher safety. From the sapwood to the transition wood and heartwood, the earlywood vessel lumen diameter of the more primitive species tended to be stable and then decrease, while that of the more evolved species gradually decreased. The latewood vessel density of the more primitive species tended to be stable and then increase, while that of the more evolved species tended to be stable. Additionally, the starch grains of the more primitive species were mainly distributed in the axial or ray parenchyma cells of the sapwood, while those of the more evolved species were abundantly distributed in the axial and ray parenchyma cells of the sapwood, and the distribution of the starch grains was reduced in the transition wood and heartwood. From the sapwood to the heartwood, the ray parenchyma cell fraction tended to be stable in the more primitive species, and tended to be stable before decreasing in the more evolved species. The pit density in the horizontal wall of the ray parenchyma cells tended to be stable and decrease in the more primitive species, while in the more evolved species it tended to be stable or decrease before stabilizing. Overall, trees’ vessels have gradually undergone the optimal selection of vessels during evolution, and the structural variation in the parenchyma cells contributes to their nutrient storage and transport.

GC-MS/MS Method for Determination of Polycyclic Aromatic Hydrocarbons in Herbal Medicines.

Polycyclic aromatic hydrocarbons (PAHs) are hydrophobic organic contaminants that have a highly carcinogenic and mutagenic nature. This study aimed to develop and validate a sensitive analytical method to determine 8 PAHs in 51 herbal medicines (HMs) using gas chromatography (GC)-tandem mass spectrometry (MS/MS). Liquid--liquid extraction and florisil SPE cartridge purification were basically adopted for pretreatment. For the samples containing essential oil, starch grain, etc., N,N-dimethyl formamide/water mixture (9:1, v/v) was added in the extraction step. The multiple reaction monitoring (MRM) conditions were newly obtained by the infusion of reference solutions of the targeted compounds at a concentration of 100 ng/mL into the GC-MS/MS system used in this study. The 51 items were classified according to whether or not they contained essential oil. Eight PAHs were not detected in 39 (8.3%) of the 459 samples monitored. The total content of 8 PAHs ranged from 0.45 μg/kg in Anemarrhenae Rhizoma to 270.94 μg/kg in Zingiberis Rhizoma. The average content of those ranged from 0.9 μg/kg in Araliae Continentalis Radix to 110.8 μg/kg in Coptidis Rhizoma Preparata cum Vinum. The results of this study prove that the proposed method is useful for determining 8 PAHs in HMs.

Effects of elevated CO2 concentration on cell structure and stress resistance physiology of Setaria italica under drought stress.

The frequency of drought will increase under further warming. The increase in atmospheric CO2 concentration, along with more frequent drought, will affect crop growth. We examined the changes of cell structure, photosynthetic physiology, antioxidant enzymes, osmotic regulatory substances, and yield of foxtail millet (Setaria ita-lica) leaves under different CO2 concentrations (ambient air CO2 concentration and ambient atmospheric CO2 concentration + 200 μmol·mol-1) and water treatment (soil moisture content maintained at 45%-55%, and 70%-80% of field capacity, representing mild drought and normal water condition, respectively). The results showed that elevated CO2 concentration increased the number of starch grains, the area of single starch grains, and the total area of starch grains in the chloroplast of millet mesophyll cells. Under mild drought condition, elevated CO2 concentration increased net photosynthetic rate of millet leaves at the booting stage by 37.9%, but did not affect water use efficiency at this stage. Elevated CO2 concentration increased net photosynthetic rate and water use efficiency of millet leaves under mild drought condition at the filling stage by 15.0% and 44.2%, respectively. Under mild drought condition, elevated CO2 concentration increased the content of peroxidase (POD) and soluble sugar in millet leaves at the booting stage by 39.3% and 8.0%, respectively, but decreased proline content by 31.5%. It increased the content of POD in millet leaves at the filling stage by 26.5% but decreased the content of MDA and proline by 37.2% and 39.3%, respectively. Under mild drought condition, elevated CO2 concentration significantly increased the number of grain spikes by 44.7% and yield by 52.3% in both years compared with normal water condition. The effect of elevated CO2 concentration on grain yield under mild drought conditions was higher than that under normal water condition. Under mild drought conditions, elevated CO2 concentration increased leaf thickness, vascular bundle sheath cross-sectional area, net photosynthetic rate, and water use efficiency of millet, improved the antioxidant oxidase activity, and changed the concentration of osmotic regulatory substances, alleviated the nega-tive effect of drought on foxtail millet, and finally increased the number of grains per ear and yield of foxtail millet. This study would provide a theoretical basis for millet production and sustainable agricultural development in arid areas under future climate change.

Creating high-resistant starch rice by simultaneous editing of SS3a and SS3b.

Creating high-resistant starch rice by simultaneous editing of SS3a and SS3b.

Pharmacognostic evaluation and antioxidant capacity of Tetracera macrophylla Hook. F. & Thoms twigs

Context: Tetracera macrophylla Hook. f. & Thoms is used empirically in traditional medicine, specifically the twig, to treat dysentery, diarrhea, diabetes, and tuberculosis symptoms. The plant contains phenolic and flavonoid compounds that offer potential as antioxidants. Aims: To evaluate the pharmacognostic characteristics of T. macrophylla, phytochemical, total phenolic and flavonoid contents, and the antioxidant capacity twig of T. macrophylla from n-hexane, ethyl acetate, and methanol extracts. Methods: Pharmacognostic evaluation was carried out by macroscopic-microscopic observation leaf and twig of the Tetracera macrophylla, and phytochemical analysis was carried out using several chemical reagents. The chromatographic profile was analyzed by thin-layer chromatography and qualitative identification of compounds by liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS). The total phenolic (TPC) and flavonoid contents (TFC) were determined colorimetrically. The antioxidant capacity was determined in vitro by the FRAP and DPPH methods. Results: The microscopic analysis of leaf powder showed the presence of raphide crystals, uniseriate trichomes, and parasitic stomata, while the twig powder showed the presence of raphide crystals. The primary phenolic compounds in the active extracts were identified as 6-hydroxy-2-(2-phenylethyl) chromone, d-catechin, isorhamnetin, and epicatechin gallate. The highest TPC and TFC were found in the ethyl acetate extract. The ethyl acetate and methanol extract showed a higher antioxidant capacity than the hexane extract. The correlation matrix between TPC, TFC, and antioxidant capacity showed a robust correlation. Conclusions: The pharmacognostic evaluation of T. macrophylla revealed the presence of characteristic morphological features of the plant. A microscopic study of the leaf showed the presence of uniseriate trichomes and paracytic stomata on the abaxial epidermis. Powder analysis of twigs showed the presence of irregular starch grains, raphide crystals, and stone cells. The TPC and TFC in twigs of T. macrophylla were robustly correlated to antioxidant capacity with the FRAP method. Meanwhile, the TPC and TFC gave a moderate correlation with DPPH methods. The ethyl acetate and methanol extracts of T. macrophylla twigs showed a higher antioxidant capacity than the n-hexane extract.

Pharmacognostic and Physicochemical evaluation of Harungana madagascariensis Lam. Ex Poir fruit (Hypericaceae)

Medicinal plant materials are being adulterated and substituted in commerce due to many reasons such as similar morphological features, same name as written in classical text, presence of similar active principles in the substituted plant which may badly affect the therapeutic activity of the finished products. As a result, authentication of medicinal plants is of paramount importance in ensuring quality and safety of crude drugs and herbal products. This research was aimed to evaluate and document the pharmacognostic standards for the fruits of Harungana madagascariensis. The plant sample was identified, collected and authenticated by a Taxonomist. Pharmacognostic and physicochemical evaluation were carried out on the powdered fruits of Harungana madagascariensis using standard methods. The result showed the presence of starch grains, lignified tissues, cellulose, and proteins while calcium oxalate and mucilage were absent. The moisture content (8.8±0.02)%, total ash value (5.2±0.005)%, acid insoluble ash (2.5±0.0)%, water soluble ash (2.2±0.01) % and extractive value were obtained. The n-hexane, ethyl acetate, n-butanol, ethanol and water soluble extractive values(3±0.00, 3.75±0.25, 4.50, 8.5±0.1, 6.25±0.25 %w/w respectively which were significantly different (at p set at 0.05). The revealed pharmacognostic features, physico-chemical and microscopy/chemomicroscopy properties of H. madagascariensis could be useful in the preparation of the herbal Pharmacopoeia.

Genome-wide association mapping in elite winter wheat breeding for yield improvement

Increased grain yield (GY) is the primary breeding target of wheat breeders. We performed the genome-wide association study (GWAS) on 168 elite winter wheat lines from an ongoing breeding program to identify the main determinants of grain yield. Sequencing of Diversity Array Technology fragments (DArTseq) resulted in 19,350 single-nucleotide polymorphism (SNP) and presence-absence variation (PAV) markers. We identified 15 main genomic regions located in ten wheat chromosomes (1B, 2B, 2D, 3A, 3D, 5A, 5B, 6A, 6B, and 7B) that explained from 7.9 to 20.3% of the variation in grain yield and 13.3% of the yield stability. Loci identified in the reduced genepool are important for wheat improvement using marker-assisted selection. We found marker-trait associations between three genes involved in starch biosynthesis and grain yield. Two starch synthase genes (TraesCS2B03G1238800 and TraesCS2D03G1048800) and a sucrose synthase gene (TraesCS3D03G0024300) were found in regions of QGy.rut-2B.2, QGy.rut-2D.1, and QGy.rut-3D, respectively. These loci and other significantly associated SNP markers found in this study can be used for pyramiding favorable alleles in high-yielding varieties or to improve the accuracy of prediction in genomic selection.

PHARMACOGNOSTIC AND ANALYTICAL STUDY OF CHANDRODAYA VARTI: AN AYURVEDIC FORMULATION

Chandrodaya varti is a herbomineral compound indicated for ophthalmic diseases. Its ingredients consist of specific properties so that they can be used in managing Garbhasya grivagata vrana (Cervical Erosion). Chandrodaya Varti constitutes 9 ingredients, of which 6 are herbal drugs, 1 mineral, 1 sea and 1 animal origin. The pharmacognostic and analytical study revealed the specific characteristics of all active constituents used in preparation. The present work was carried out to standardize the finished product of Chandrodaya varti to confirm its identity, quality and purity. The presence of oil globules, starch grains, stone cells, macro sclereids stone cells, rhizome and prismatic crystal were the microscopic features of the powder of the prepared drug. Physiochemical analysis of Chandrodaya varti showed a loss on drying value of 8.9%, a water-soluble extractive value of 36.1%, alcohol soluble extractive of 26.9%, total ash of 10.9%, acid insoluble ash of 10.8%, pH 5.85 and the physicochemical analysis of Chandrodaya varti ash showed the loss on drying 0.01%, water-soluble extractive 34.4%, alcohol soluble extractive 9.8% and pH 13.37. HPTLC of Chandrodaya varti is the preliminary quantitative analysis which shows 11 spots at Rf value 0.11, 0.15, 0.21, 0.28, 0.31, 0.38, 0.47, 0.54, 0.62, 0.68, 0.79 in UV 254 nm and 11 spots at Rf value 0.15, 0.21, 0.31, 0.38, 0.42, 0.50, 0.54, 0.62, 0.79, 0.82, 0.89 in UV 366 nm and 7 spots at Rf value 0.15, 0.31, 0.42, 0.50, 0.54, 0.62, 0.79 in UV 540 nm.

Identification and characterization of the chalkiness endosperm gene CHALK-H in rice (Oryza sativa L.)

Chalkiness is one of the most important agronomic traits in rice breeding, which directly affects the quality of rice seed. In this study, we identified a chalkiness endosperm mutant, chalk-h, from N-methyl-N-nitrosourea (MNU)-induced japonica rice cultivar Hwacheong (HC). Compared with wild type (WT)-HC, chalk-h showed severe chalkiness in the endosperm, yellowish green leaves, as well as reduced plant height. Scanning electron microscopy (SEM) analysis showed that starch grains in the chalk-h mutant were irregular in size and loosely arranged, with large gaps between granules, forming ovoid or orbicular shapes. MutMap analysis revealed that the phenotype of chalk-h is controlled by a single recessive gene LOC_Os11g39670 encoding seryl-tRNA synthetase, which is renamed as CHALK-H. A point mutation occurs in chalk-h on the sixth exon (at nucleotide 791) of CHALK-H, in which adenine (A) is replaced by thymidine (T), resulting in an amino acid codon change from glutamine (Glu) to valine (Val). The chalk-h mutant exhibited a heat-sensitive phenotype from the 3-leaf stage, including yellow-green leaves and reduced pigment content. The transcriptional expression of starch synthesis-related genes was down-regulated in the chalk-h mutants compared to WT-HC at different grain-filling stages. With an increase in temperature, the expression of photosynthesis-related genes was down-regulated in the chalk-h mutant compared to WT-HC. Overexpression of CHALK-H rescued the phenotype of chalk-h, with endosperm and leaf color similar to those of WT-HC. Our findings reveal that CHALK-H is a causative gene controlling chalkiness and leaf color of the chalk-h mutant. CHALK-H is the same gene locus as TSCD11, which was reported to be involved in chloroplast development under high temperature. We suggest that CHALK-H/TSCD11 plays important roles not only in chloroplast development, but also in photosynthesis and starch synthesis during rice growth and development, so it has great application potential in rice breeding for high quality and yield.

TabHLH95-TaNF-YB1 module promotes grain starch synthesis in bread wheat

Starch is the most abundant substance in wheat (Triticum aestivum L.) endosperm and provides the major carbohydrate energy for human daily life. Starch synthesis-related (SSR) genes are believed to be spatiotemporally specific, but their transcriptional regulation remains unclear in wheat. Here, we investigate the role of the basic helix-loop-helix (bHLH) transcription factor TabHLH95 in starch synthesis. TabHLH95 is preferentially expressed in the developing grains in wheat and encodes a nucleus localized protein without autoactivation activity. The Tabhlh95 knockout mutants display smaller grain size and less starch content than wild type, whereas overexpression of TabHLH95 enhances starch accumulation and significantly improves thousand grain weight. Transcriptome analysis reveals that the expression of multiple SSR genes is significantly reduced in the Tabhlh95 mutants. TabHLH95 binds to the promoters of ADP-glucose pyrophosphorylase large subunit 1 (AGPL1-1D/-1B), AGPL2-5D, and isoamylase (ISA1-7D) and enhances their transcription. Intriguingly, TabHLH95 interacts with the nuclear factor Y (NF-Y) family transcription factor TaNF-YB1, thereby synergistically regulating starch synthesis. These results suggest that the TabHLH95-TaNF-YB1 complex positively modulates starch synthesis and grain weight by regulating the expression of a subset of SSR genes, thus providing a good potential approach for genetic improvement of grain productivity in wheat.

Metabolomic exploration of the physiological regulatory mechanism of the growth and metabolism characteristics of Chlorella vulgaris under photoautotrophic, mixotrophic, and heterotrophic cultivation conditions

Microalgae have various trophic modes such as photoautotrophy, mixotrophy, and heterotrophy, and the physiological and metabolic processes of algal cells in different trophic modes are different. To explore the mechanism underlying trophic mode-mediated regulation of the physiological metabolism of microalgae, Chlorella vulgaris 31 was cultivated under photoautotrophic, mixotrophic, and heterotrophic conditions. Mixotrophic and heterotrophic cultivation significantly promoted the growth, biomass, and lipid and saccharide biosynthesis of C. vulgaris, while higher photosynthetic pigment and protein content could be obtained under autotrophic conditions. Flow cytometry analysis revealed that light periodically and significantly regulated agal cell growth under the photoautotrophic condition, but a weakened effect was observed under mixotrophic and heterotrophic conditions. The mitochondrial structure was affected by enhanced aerobic respiration under mixotrophic and heterotrophic modes. Moreover, the accumulation of starch grains and lipid droplets was significantly higher than that in the photoautotrophic control; however, no significant changes were observed in the chloroplast and nucleus. Intracellular metabolites in mixotrophic and heterotrophic modes varied markedly, mainly involving saccharides, organic acids, fatty acids, and amino acids. Metabolic pathway analysis indicated that mixotrophy and heterotrophy could significantly enhance glycolysis, the tricarboxylic acid cycle, and the pentose phosphate pathway on the 3rd day of cultivation, while higher acetyl-CoA levels were available for fatty acid synthesis in the stationary phase. This finding clarified the mechanism of mixotrophic and heterotrophic growth of C. vulgaris for biomass and biomolecule production.

Morpho-physiological trait variation of pre-harvest sprouting tolerance to simulated rain in mungbean (Vigna radiata)

Preharvest sprouting (PHS) is one of the most important factors for lower productivity in mungbean [Vigna radiata(L.) R. Wilczek]. The morpho-physiological characters, ultra-structural variations in pods and seeds, changes andregulatory water absorption pathway of 30 mungbean genotypes in relation to pre-harvest sprouting behaviour wasstudied during kharif 2017–19 at Seed Research Technology Center, Indian Institute of Rice Research, Rajendranagar, Hyderabad, Telangana. Mungbean genotypes subjected to PHS imposed by simulated rainfall were evaluated. Rainfall simulator generates a rainfall spectrum that was similar to natural rainfall. Genotypes LGG 450 and K 851 with low score (%), while ML 267 and MGG 295 with high score (%) were screened as tolerant and susceptible to PHS. Accordingly, higher seed yield was recorded in LGG 450 (4.94 g/plant) followed by K 851 (4.20 g/plant) while lower seed yield was recorded in ML 267 (0.26 g/plant) followed by MGG 295 (0.79 g/plant). The findings were further corroborated with SEM studies by presence of sparse, wiry, short, twist or shriveled trichomes; thick cuticular pod wall, wide locular gap between seed coat (seed) and pod wall helping for the slow diffusion of moisture from endosperm to embryo. Further, the presence of lea-protein-insulated starch grains of endosperm merits lipophilic nature which might hindered dissipation of water to embryo via endosperm. The SEM studies have established ultrastructural features that determine the resistance to pre-harvest sprouting of mungbean and development of future resistant lines identification.