LE-SSL-MOS: Self-Supervised Learning MOS Prediction with Listener Enhancement

Recently, researchers have shown an increasing interest in automatically predicting the subjective evaluation for speech synthesis systems. This prediction is a challenging task, especially on the out-of-domain test set. In this paper, we proposed a novel fusion model for MOS prediction that combines supervised and unsupervised approaches. In the supervised aspect, we developed an SSL-based predictor called LE-SSL-MOS. The LE-SSL-MOS utilizes pre-trained self-supervised learning models and further improves prediction accuracy by utilizing the opinion scores of each utterance in the listener enhancement branch. In the unsupervised aspect, two steps are contained: we fine-tuned the unit language model (ULM) using highly intelligible domain data to improve the correlation of an unsupervised metric - SpeechLMScore. Another is that we utilized ASR confidence as a new metric with the help of ensemble learning. To our knowledge, this is the first architecture that fuses supervised and unsupervised methods for MOS prediction. With these approaches, our experimental results on the VoiceMOS Challenge 2023 show that LE-SSL-MOS performs better than the baseline. Our fusion system achieved an absolute improvement of 13% over LE-SSL-MOS on the noisy and enhanced speech track. Our system ranked 1st and 2nd, respectively, in the French speech synthesis track and the challenge's noisy and enhanced speech track.Comment: accepted in IEEE-ASRU202

Molecular cloning, characterization and expression analysis of CpCBF2 gene in harvested papaya fruit under temperature stresses

Background: C-repeat binding factors (CBFs) are transcription factors that regulate the expression of a number of genes related to abiotic stresses. Few CBF genes have been cloned from other plants but no report in papaya. In present study, a full-length cDNA, designated as CpCBF2, was cloned from papaya using in silico cloning and 5\u2019- rapid amplification cDNA ends (RACE). Sequence analysis was performed to understand the gene function. The expression pattern of CpCBF2 in papaya under low (7\ubaC) and high temperature (35\ubaC) stresses was examined using real-time quantitative polymerase chain reaction (RT-qPCR). Results: The full-length cDNA of CpCBF2 was 986-bp, with a 762-bp open reading frame (ORF) encoding a 254 amino acid polypeptide. CpCBF2 contained several major highly conserved regions including the CBF-family signature PKRRAGRKKFQETRHP and FADSAW in its amino acid sequence. Phylogenetic tree and three-dimensional structure analysis showed that CpCBF2 had a relatively close relationship with other plant CBFs. Gene expression analysis showed that high temperature stress had little effect on the expression of CpCBF2 but low temperature repressed CpCBF2 expression. Conclusion: The results showed that CpCBF2 may involve in different roles in temperature stress tolerance. This study provided a candidate gene potentially useful for fruit temperature stress tolerance, although its function still needs further confirmation

Auxin response factor 6A regulates photosynthesis, sugar accumulation, and fruit development in tomato.

Auxin response factors (ARFs) are involved in auxin-mediated transcriptional regulation in plants. In this study, we performed functional characterization of SlARF6A in tomato. SlARF6A is located in the nucleus and exhibits transcriptional activator activity. Overexpression of SlARF6A increased chlorophyll contents in the fruits and leaves of tomato plants, whereas downregulation of SlARF6A decreased chlorophyll contents compared with those of wild-type (WT) plants. Analysis of chloroplasts using transmission electron microscopy indicated increased sizes of chloroplasts in SlARF6A-overexpressing plants and decreased numbers of chloroplasts in SlARF6A-downregulated plants. Overexpression of SlARF6A increased the photosynthesis rate and accumulation of starch and soluble sugars, whereas knockdown of SlARF6A resulted in opposite phenotypes in tomato leaves and fruits. RNA-sequence analysis showed that regulation of SlARF6A expression altered the expression of genes involved in chlorophyll metabolism, photosynthesis and sugar metabolism. SlARF6A directly bound to the promoters of SlGLK1, CAB, and RbcS genes and positively regulated the expression of these genes. Overexpression of SlARF6A also inhibited fruit ripening and ethylene production, whereas downregulation of SlARF6A increased fruit ripening and ethylene production. SlARF6A directly bound to the SAMS1 promoter and negatively regulated SAMS1 expression. Taken together, these results expand our understanding of ARFs with regard to photosynthesis, sugar accumulation and fruit development and provide a potential target for genetic engineering to improve fruit nutrition in horticulture crops

Ethylene regulation of fruit softening and cell wall disassembly in Charentais melon

Cell wall disassembly in ripening fruit is highly complex, involving the dismantling of multiple polysaccharide networks by diverse families of wall-modifying proteins. While it has been reported in several species that multiple members of each such family are expressed in the same fruit tissue, it is not clear whether this reflects functional redundancy, with protein isozymes from a single enzyme class performing similar roles and contributing equally to wall degradation, or whether they have discrete functions, with some isoforms playing a predominant role. Experiments reported here sought to distinguish between cell wall-related processes in ripening melon that were softening-associated and softening-independent. Cell wall polysaccharide depolymerization and the expression of wall metabolism-related genes were examined in transgenic melon (Cucumis melo var. cantalupensis Naud.) fruit with suppressed expression of the 1-aminocyclopropane-1-carboxylate oxidase (ACO) gene and fruits treated with ethylene and 1-methylcyclopropene (1-MCP). Softening was completely inhibited in the transgenic fruit but was restored by treatment with exogenous ethylene. Moreover, post-harvest application of 1-MCP after the onset of ripening completely halted subsequent softening, suggesting that melon fruit softening is ethylene-dependent. Size exclusion chromatography of cell wall polysaccharides, from the transgenic fruits, with or without exogenous ethylene, indicated that the depolymerization of both pectins and xyloglucans was also ethylene dependent. However, northern analyses of a diverse range of cell wallrelated genes, including those for polygalacturonases, xyloglucan endotransglucosylase/hydrolases, expansin, and b-galactosidases, identified specific genes within single families that could be categorized as ethylene-dependent, ethylene-independent, or partially ethylene-dependent. These results support the hypothesis that while individual cell wall-modifying proteins from each family contribute to cell wall disassembly that accompanies fruit softening, other closely related family members are regulated in an ethylene-independent manner and apparently do not directly participate in fruit softening

Expression of ethylene-related expansin genes in cool-stored ripening banana fruit

Expansins are cellular proteins expressed in the course of cell wall loosening during fruit ripening. There is no information about the relationship between expansins and ripening of chilling injury (CI)-affected banana fruit. Banana fruit were pre-treated with 0 or 1000 mu L/L propylene (functional ethylene analogue) for 16 h and then stored at 7 degrees C. Cl symptoms of untreated control fruit appeared after 4 days, while propylene pre-treated fruit showed CI symptoms after 7 days. Thus, stimulation of ripening with propylene applied prior to storage at low temperature tended to alleviate Cl. The fruit were stored for 8 days at 7 degrees C and then transferred to 22 degrees C, followed by treatment with 1000 mu L/L propylene to initiate ripening. The propylene treatment accelerated color change, increased ethylene production rate and caused a more rapid decrease in peel and pulp firmness. Two banana expansins, AY083168 and AF539540 (GeneBank), were chosen as the target genes MaExp1 and MaExp2, respectively. RNA blotting analysis showed no accumulation of either MaExp1 or MaExp2 transcripts in banana fruit during low temperature storage. Expansin genes were expressed more intensively in propylene pre-treated fruit than in control fruit upon removal from cold storage for propylene-initiated ripening. The results suggest that increased tolerance of banana fruit pre-treated with propylene to low temperature-induced chilling was related to higher post-storage ethylene production rates and enhanced expression of MaExp1 and MaExp2. (c) 2006 Elsevier Ireland Ltd. All rights reserved

A Banana PHD-Type Transcription Factor MaPHD1 Represses a Cell Wall-Degradation Gene MaXTH6 during Fruit Ripening

Plant homeobox domain (PHD)-type transcription factors (TFs) are involved in a variety of biological processes. However, its involvement in commercially important fruit ripening process remains largely unclear. In the present work, the characterization of a PHD-type TF termed MaPHD1 from banana fruit is reported. Multiple alignments of the deduced amino acid sequence revealed that MaPHD1 showed a high homology with Arabidopsis thaliana Alfin1-like proteins belonging to plant-specific sub-family of PHD finger proteins. MaPHD1 was found localized in the nucleus and exhibited trans-repression ability. It was down-regulated by ethylene and ripening. Electrophoretic Mobility Shift Assay (EMSA) and transient expression analysis demonstrated that MaPHD1 directly bound to the G-rich motifs in the promoter of MaXTH6, which is associated with cell wall degradation, and subsequently repressed its expression. These findings suggest that MaPHD1 may be negatively associated with banana fruit ripening, at least in part, by the direct suppression of MaXTH6. Taken together, these findings provide new insights into the transcriptional regulatory networks of banana fruit ripening

Molecular Characterization of a Leaf Senescence-Related Transcription Factor BrWRKY75 of Chinese Flowering Cabbage

WRKY is a plant-specific transcription factor (TF) involved in the regulation of many biological processes; however, its role in leaf senescence of leafy vegetables remains unknown. In the present work, a WRKY TF, termed BrWRKY75 was isolated from Chinese flowering cabbage [Brassica rapa L. ssp. chinensis (L.) Mokino var. utilis Tsen et Lee]. Analysis of deduced amino acid sequence and the phylogenetic tree showed that BrWRKY75 has high homology with WRKY75 from Brassica oleracea and Arabidopsis thaliana, and belongs to the II c sub-group. Sub-cellular localization and transcriptional activity analysis revealed that BrWRKY75 is a nuclear protein with transcriptional repression activity, and was up-regulated during leaf senescence. Electrophoretic mobility shift assay confirmed that BrWRKY75 directly bound to the W-box (TTGAC) cis-element. Collectively, these results provide a basis for further investigation of the transcriptional regulation of Chinese flowering cabbage leaf senescence

Arabidopsis BREVIPEDICELLUS interacts with the SWI2/SNF2 chromatin remodeling ATPase BRAHMA to regulate KNAT2 and KNAT6 expression in control of inflorescence architecture.

BREVIPEDICELLUS (BP or KNAT1), a class-I KNOTTED1-like homeobox (KNOX) transcription factor in Arabidopsis thaliana, contributes to shaping the normal inflorescence architecture through negatively regulating other two class-I KNOX genes, KNAT2 and KNAT6. However, the molecular mechanism of BP-mediated transcription regulation remains unclear. In this study, we showed that BP directly interacts with the SWI2/SNF2 chromatin remodeling ATPase BRAHMA (BRM) both in vitro and in vivo. Loss-of-function BRM mutants displayed inflorescence architecture defects, with clustered inflorescences, horizontally orientated pedicels, and short pedicels and internodes, a phenotype similar to the bp mutants. Furthermore, the transcript levels of KNAT2 and KNAT6 were elevated in brm-3, bp-9 and brm-3 bp-9 double mutants. Increased histone H3 lysine 4 tri-methylation (H3K4me3) levels were detected in brm-3, bp-9 and brm-3 bp-9 double mutants. Moreover, BRM and BP co-target to KNAT2 and KNAT6 genes, and BP is required for the binding of BRM to KNAT2 and KNAT6. Taken together, our results indicate that BP interacts with the chromatin remodeling factor BRM to regulate the expression of KNAT2 and KNAT6 in control of inflorescence architecture