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Abstract Background Grain endosperm chalkiness of rice is a varietal characteristic that negatively affects not only the appearance and milling properties but also the cooking texture and palatability of cooked rice. However, grain chalkiness is a complex quantitative genetic trait and the molecular mechanisms underlying its formation are poorly understood. Results A near-isogenic line CSSL50-1 with high chalkiness was compared with its normal parental line Asominori for grain endosperm chalkiness. Physico-biochemical analyses of ripened grains showed that, compared with Asominori, CSSL50-1 contains higher levels of amylose and 8 DP (degree of polymerization) short-chain amylopectin, but lower medium length 12 DP amylopectin. Transcriptome analysis of 15 DAF (day after flowering) caryopses of the isogenic lines identified 623 differential expressed genes (P < 0.01), among which 324 genes are up-regulated and 299 down-regulated. These genes were classified into 18 major categories, with 65.3% of them belong to six major functional groups: signal transduction, cell rescue/defense, transcription, protein degradation, carbohydrate metabolism and redox homeostasis. Detailed pathway dissection demonstrated that genes involved in sucrose and starch synthesis are up-regulated, whereas those involved in non-starch polysaccharides are down regulated. Several genes involved in oxidoreductive homeostasis were found to have higher expression levels in CSSL50-1 as well, suggesting potential roles of ROS in grain chalkiness formation. Conclusion Extensive gene expression changes were detected during rice grain chalkiness formation. Over half of these differentially expressed genes are implicated in several important categories of genes, including signal transduction, transcription, carbohydrate metabolism and redox homeostasis, suggesting that chalkiness formation involves multiple metabolic and regulatory pathways.

Fat content (FC) is an important component of the nutritional quality of the rice (Oryza sativa L.) grain and a partial determinant of grain quality. Three FC QTLs were identified from an analysis of a set of rice 'Kasalath'/'Koshihikari' backcross inbred lines, which were grown in three independent environments. Two of these QTLs (qFC7.1 and qFC7.2) were located on chromosome 7, and they were detected in all three environments. The presence of qFC7.1 and qFC7.2 was further confirmed by testing a set of 'Kasalath' (donor) / 'Koshihikari' (recipient) chromosome segment substitution lines (CSSLs) across six environments. Both QTLs significantly increased grain FC and they might be involved in lipid metabolism. The two QTLs were stably expressed in a number of environments and populations, making them suitable candidates for the improvement of FC via marker assisted breeding. Key words: rice (Oryza sativa L.), fat content, protein content, QTL mapping. Le teneur en lipides (FC pour << fat content >>) est une composante importante de la qualite nutritionnelle du grain de riz (Oryza sativa L.) et determine en partie la qualite du grain. Trois QTL pour le FC ont ete identifies au terme de l'analyse d'une serie de lignees retrocroisees 'Kasalath'/'Koshihikari', lesquelles ont ete cultivees dans trois environnements independants. Deux de ces QTL (qFC7,1 et qFC7,2) sont situes sur le chromosome 7 et ont ete detectes dans les trois environnements. La presence de qFC7,1 et qFC7,2 a ete confirmee au sein de lignees de substitution pour des segments chromosomiques (CSSL) issues du croisement 'Kasalath' (donneur) / 'Koshihikari' (receveur), lesquelles ont ete cultivees dans six environnements. Les deux QTL contribuaient a augmenter significativement la teneur en lipides et l'emplacement genomique de qFC7,2 suggere que celui-ci serait implique dans le metabolisme des lipides. Les deux QTL ont ete exprimes de maniere stable au sein de plusieurs environnements et populations, ce qui en fait des candidats attrayants pour l' amelioration de la teneur en lipides par selection assistee de marqueurs. Mots-cles : riz (Oryza sativa L.), teneur en lipides, teneur en proteines, cartographie QTL. [Traduit par la Redaction], Introduction The fat fraction of the rice (Oryza sativa L.) grain, which is composed mainly of triacylglycerols, is largely concentrated in the embryo and the aleurone. Its biological function is [...]

Heat stress is one of the major abiotic stresses that adversely affect growth and yield inLentinula edodes(Shiitake mushroom) under natural cultivation. In this study, two parental strains (L808 and Lsm9), an F1strain, and an F2population derived from their hybrid progeny were used to evaluate the regeneration of mycelia after heat stress. A multi-level heat stress experiment showed that the dynamics of radial mycelium expansion of the two parents followed a linear equation after heat stress treatment at 37°C for 4–24 h, 42°C for 4–16 h, or 45°C for 4 h. Three indices were selected to describe the regeneration ability of the strains, including the number of regeneration days (NRD), the real growth rate after heat stress (Vregeneration), and the regenerative index (RI). L808 presented a faster rate of regeneration, while Lsm9 had better regeneration quality. The phenotype analysis of the F2population showed that these indices were controlled by multiple genetic factors with high heritability. Four strains were selected from the population, pyramiding the advantages of heat resistance from the two parents. The results will help our understanding of the genetic features of this mushroom after extreme high-temperature stress. [ABSTRACT FROM PUBLISHER]

Highlights: [•] We model the change of substrate temperature with stimulus time. [•] Increasing stimulus time will enhance initiation and yield at the same temperature. [ • ] Time and temperature×time are the two major factors that affect initiation and yield. [•] The best performance was recorded following a 12h cold stimulation at 5°C. [ABSTRACT FROM AUTHOR]

The Isaria cicadae , is well known highly prized medicinal mushroom with great demand in food and pharmaceutical industry. Due to its economic value and therapeutic uses, natural sources of wild I. cicadae are over-exploited and reducing continuously. Therefore, commercial cultivation in controlled environment is an utmost requirement to fulfill the consumer's demand. Due to the lack of knowledge on fruiting body (synnemata) development and regulation, commercial cultivation is currently in a difficult situation. In the growth cycle of macrofungi, such as mushrooms, light is the main factor affecting growth and development, but so far, specific effects of light on the growth and development of I. cicadae is unknown. In this study, we identified a blue light receptor white-collar-1 ( Icwc-1 ) gene homologue with well-defined functions in morphological development in I. cicadae based on gene knockout technology and transcriptomic analysis. It was found that the Icwc-1 gene significantly affected hyphal growth and fruiting body development. This study confirms that Icwc-1 acts as an upstream regulatory gene that regulates genes associated with fruiting body formation, pigment-forming genes, and related genes for enzyme synthesis. Transcriptome data analysis also found that Icwc-1 affects many important metabolic pathways of I. cicadae , i.e., amino acid metabolism and fatty acid metabolism. The above findings will not only provide a comprehensive understanding about the molecular mechanism of light regulation in I. cicadae , but also provide new insights for future breeding program and improving this functional food production., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Song, Shrivastava, Gai, Li, Cai, Shen, Lin, Liu and Wang.)

Agaricus bisporus growth alters the lignocellulosic composition and structure of compost. However, it is difficult to differentiate the enzyme activities of A. bisporus mycelia from the wider microbial community owing to the complication of completely speareting the mycelia from compost cultures. Macrogenomics analysis was employed in this study to examine the fermentation substrate of A. bisporus before and after mycelial growth, and the molecular mechanism of substrate utilization by A. bisporus mycelia was elucidated from the perspective of microbial communities and CAZymes in the substrate. The results showed that the relative abundance of A. bisporus mycelia increased by 77.57-fold after mycelial colonization, the laccase content was significantly increased and the lignin content was significantly decreased. Analysis of the CAZymes showed that AA10 family was extremely differentiated. Laccase-producing strains associated with AA10 family were mostly bacteria belonging to Thermobifida and Thermostaphylospora , suggesting that these bacteria may play a synergistic role in lignin decomposition along with A. bisporus mycelia. These findings provide preliminary evidence for the molecular mechanism of compost utilization by A. bisporus mycelia and offer a reference for the development and utilization of strains related to lignocellulose degradation., Competing Interests: The authors declare there are no competing interests., (©2022 Chang et al.)

In this study, the complete mitochondrial genome of Sanghuangporus vaninii Zhehuang-1 was determined. Genomic DNA samples individually collected from a population in southeastern China (Qiandaohu, Zhejiang Province, N29°44'24'', E118°52'48'') were sequenced with an Illumina NovaSeq 6000. The complete mitochondrial genome was 97,345 bp in length and consisted of 22 protein-coding genes (PCGs), 29 tRNAs, 3 ribosomal RNAs, and a control region. Sanghuangporus vaninii has a mitochondrial gene arrangement that is similar to that of S. sanghuang . Phylogenetic analysis performed using ML methods based on the complete mitogenome sequence showed that S. vaninii is a member of the Polyporaceae. The complete mitogenome sequence provides important data for further study of the Inonotus linteus complex., Competing Interests: No potential conflict of interest was reported by the author(s)., (© 2021 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.)

Agricultural straws (AS) may serve as potential base-substances in the production of Agaricus bisporus . Six AS that occur across China were investigated in a two-stage composting experiment; lignocellulose components, AS morphology, and the effects of different AS on mushroom yields from 2015-2017 were examined. In addition, microbial biodiversity and their impact on substrate degradation were studied using 16S gene sequenc based on six different AS on the 3rd (I.F), 6th (I.S), and 10th (I.T) day of Phase I, and Phase II (II). Results showed that the six different AS exhibited differences in the progression of degradation under the same compost condition; the wheat straw, rice straw, and cotton straw induced a significantly higher mushroom yield than did the others ( P < 0.05); Thermobispora , Thermopolyspora, and Vulgatibacter genera may play an important role in the different AS degradations. According to our experiments, we can adjust formulations and compost methods to obtain high-yield mushroom compost based on different AS in the future., Competing Interests: The authors declare there are no competing interests., (©2021 Song et al.)

Light plays an important role in the growth and differentiation of Lentinula edodes mycelia, and mycelial morphology is influenced by light wavelengths. The blue light-induced formation of brown film on the vegetative mycelial tissues of L. edodes is an important process. However, the mechanisms of L. edodes ' brown film formation, as induced by blue light, are still unclear. Using a high-resolution liquid chromatography-tandem mass spectrometry integrated with a highly sensitive immune-affinity antibody method, phosphoproteomes of L. edodes mycelia under red- and blue-light conditions were analyzed. A total of 11,224 phosphorylation sites were identified on 2,786 proteins, of which 9,243 sites on 2,579 proteins contained quantitative information. In total, 475 sites were up-regulated and 349 sites were down-regulated in the blue vs red group. To characterize the differentially phosphorylated proteins, systematic bioinformatics analyses, including gene ontology annotations, domain annotations, subcellular localizations, and Kyoto Encyclopedia of Genes and Genomes pathway annotations, were performed. These differentially phosphorylated proteins were correlated with light signal transduction, cell wall degradation, and melanogenesis, suggesting that these processes are involved in the formation of the brown film. Our study provides new insights into the molecular mechanisms of the blue light-induced brown film formation at the post-translational modification level., Competing Interests: The authors declare there are no competing interests., (©2020 Song et al.)