Background: Blueberry (Vaccinium corymbosumL.) is an important species with a high content of flavonoids in fruits. As a perennial shrub, blueberry is characterized by shallow-rooted property and susceptible to drought stress. MYB transcription factor was reported to be widely involved in plant response to abiotic stresses, however, the role of MYB family in blueberry responding to drought stress remains elusive.Results: In this study, we conducted a comprehensive analysis of VcMYBs in blueberry based on the genome data under drought stress, including phylogenetic relationship, identification of differentially expressed genes (DEGs), expression profiling, conserved motifs, expression correlation and protein-protein interaction prediction, etc. The results showed that 229 non-redundant MYB sequences were identified in the blueberry genome, and divided into 23 subgroups. A total of 102 MYB DEGs with a significant response to drought stress were identified, of which 72 in leaves and 69 in roots, and 8 differential expression genes with a > 20-fold change in the level of expression. 17 DEGs had a higher expression correlation with other MYB members. The interaction partners of the key VcMYB proteins were predicted by STRING analysis and in combination with physiological and morphological observation. 10 keyVcMYBgenes such asVcMYB8, VcMYB102andVcMYB228were predicted to be probably involved in reactive oxygen species (ROS) pathway, and 7 keyVcMYBgenes (VcMYB41,VcMYB88andVcMYB100, etc..) probably participated in leaf regulation under drought treatment.Conclusions: Our studies provide a new understanding of the regulation mechanism ofVcMYBfamily in blueberry response to drought stress, and lay fundamental support for future studies on blueberry grown in regions with limited water supply for this crop.

The NAC family of transcription factors (TFs) regulate plant development and abiotic stress. However, the specific function and response mechanism of NAC TFs that increase drought resistance in Picea wilsonii remain largely unknown. In this study, we functionally characterized a member of the PwNAC family known as PwNAC31. PwNAC31 is a nuclear-localized protein with transcriptional activation activity and contains an NAC domain that shows extensive homology with ANAC072 in Arabidopsis. The expression level of PwNAC31 is significantly upregulated under drought and ABA treatments. The heterologous expression of PwNAC31 in atnac072 Arabidopsis mutants enhances the seed vigor and germination rates and restores the hypersensitive phenotype of atnac072 under drought stress, accompanied by the up-regulated expression of drought-responsive genes such as DREB2A (DEHYDRATION-RESPONSIVE ELEMENT BINDING PROTEIN 2A) and ERD1 (EARLY RESPONSIVE TO DEHYDRATION STRESS 1). Yeast two-hybrid and bimolecular fluorescence complementation assays confirmed that PwNAC31 interacts with DREB2A and ABF3 (ABSCISIC ACID-RESPONSIVE ELEMENT-BINDING FACTOR 3). Yeast one-hybrid and dual-luciferase assays showed that PwNAC31, together with its interaction protein DREB2A, directly regulated the expression of ERD1 by binding to the DRE element of the ERD1 promoter. Collectively, our study provides evidence that PwNAC31 activates ERD1 by interacting with DREB2A to enhance drought tolerance in transgenic Arabidopsis.

Research Highlights: Phenotypic changes and expression profiles, phylogeny, conserved motifs, and expression correlations of NAC (NAM, ATAF1, ATAF2 and CUC2) transcription factors (TFs) in blueberry genome were detected under drought stress, and the expression patterns and functions of 12 NACs were analyzed. Background and Objectives: Blueberry is an important shrub species with a high level of flavonoids in fruit, which are implicated in a broad range of health benefits. However, the molecular mechanism of this shrub species in response to drought stress still remains elusive. NAC TFs widely participate in stress tolerance in many plant species. The characterization and expression profiles of NAC TFs were analyzed on the basis of genome data in blueberry when subjected to drought stress. Materials and Methods: Combined with the analysis of chlorophyll a fluorescence and endogenous phytohormones, the phenotypic changes of blueberry under drought stress were observed. The phylogenetic tree, conserved motifs, differently expressed genes, and expression correlation were determined by means of multiple bioinformatics analysis. The expression profiles of NACs in different organs were examined and compared through RNA-seq and qRT-PCR assay. Results: The chlorophyll a fluorescence parameters φ_Po, φ_Eo, φ_Ro, and PIabs of leaves were significantly inhibited under drought stress. ABA (abscisic acid) content noticeably increased over the duration of drought, whereas GA₃ (gibberellic acid) and IAA (indole acetic acid) content decreased continuously. A total of 158 NACs were identified in blueberry genome and 62 NACs were differently expressed in leaf and root of blueberry under drought stress. Among them, 14 NACs were significantly correlated with the expression of other NAC genes. Conclusions: Our results revealed the phenotypic changes of this shrub under drought stress and linked them with NAC TFs, which are potentially involved in the process of response to drought stress.

Camellia (C.) oleifera Abel. is an evergreen small arbor with high economic value for producing edible oil that is well known for its high level of unsaturated fatty acids. The yield formation of tea oil extracted from fruit originates from the leaves, so leaf senescence, the final stage of leaf development, is an important agronomic trait affecting the production and quality of tea oil. However, the physiological characteristics and molecular mechanism underlying leaf senescence of C. oleifera are poorly understood. In this study, we performed physiological observation and de novo transcriptome assembly for annual leaves and biennial leaves of C. oleifera. The physiological assays showed that the content of chlorophyll (Chl), soluble protein, and antioxidant enzymes including superoxide dismutase, peroxide dismutase, and catalase in senescing leaves decreased significantly, while the proline and malondialdehyde concentration increased. By analyzing RNA-Seq data, we identified 4645 significantly differentially expressed unigenes (DEGs) in biennial leaves with most associated with flavonoid and phenylpropanoid biosynthesis and phenylalanine metabolism pathways. Among these DEGs, 77 senescence-associated genes (SAGs) including NOL, ATAF1, MDAR, and SAG12 were classified to be related to Chl degradation, plant hormone, and oxidation pathways. The further analysis of the 77 SAGs based on the Spearman correlation algorithm showed that there was a significant expression correlation between these SAGs, suggesting the potential connections between SAGs in jointly regulating leaf senescence. A total of 162 differentially expressed transcription factors (TFs) identified during leaf senescence were mostly distributed in MYB (myeloblastosis), ERF (Ethylene-responsive factor), WRKY, and NAC (NAM, ATAF1/2 and CUCU2) families. In addition, qRT-PCR analysis of 19 putative SAGs were in accordance with the RNA-Seq data, further confirming the reliability and accuracy of the RNA-Seq. Collectively, we provide the first report of the transcriptome analysis of C. oleifera leaves of two kinds of age and a basis for understanding the molecular mechanism of leaf senescence.

Chinese kale sprouts are widely cultivated and consumed due to their elevated nutritional worth and ease of cultivation in controlled environments. This study focused on the effects of several light types (white, red, and blue) both by themselves and in conjunction with calcium chloride (CaCl₂) on the physiological development and nutritional value of Chinese kale sprouts. Analysis proved that under differing light treatments, white light resulted in the highest pigment content, and red light markedly increased plant height, fresh mass, and soluble sugar accumulation. Additionally, blue light significantly enhanced the antioxidant capacity. When light quality and calcium chloride were applied together, fresh mass increased by 9.50%, 9.85%, and 12.47% (compared with single light treatments), and significantly elevated the indolic glucosinolate content. Besides, red light combined with calcium chloride also enhanced the antioxidant capacity (ferric reducing antioxidant power (FRAP) content) compared with red light alone, increasing by 14.31%. This research determined that red light in conjunction with calcium chloride obtained the highest yield of sprouts, and it can also offer new strategies for increasing the antioxidant capacity, while the blue light in conjunction with calcium chloride can provide more ways for accumulating glucosinolates. In conclusion, incorporating light quality and calcium chloride treatments in Chinese kale sprout cultivation is an effective approach for increasing yield and quality.

In this study, we analyzed the nutritional components and antioxidant capacity of 17 leaf mustard cultivars, including 13 cultivars from Leshan, 2 from Ya’an, and 2 from Yibin. Significant variations were observed among the cultivars in terms of their nutritional composition and antioxidant properties. Our findings revealed that cultivar LS12 exhibited the highest levels of total chlorophyll, total anthocyanidin, flavonoids, total phenolics, and ferric-reducing antioxidant power (FRAP). Cultivar YB2 showed higher contents of soluble sugar, soluble protein, ABTS antioxidant capacity, and total glucosinolates. On a regional basis, the cultivars from Leshan had higher total phenolics compared to those from Ya’an and Yibin, while cultivars from Yibin exhibited the highest total glucosinolate content. Additionally, purple-leaf mustard demonstrated superior flavonoid and total phenolic contents, as well as higher FRAP values, compared to the cultivars of green-leaf mustard. However, green-leaf mustard contained higher levels of total glucosinolates than their purple counterpart. Based on a comprehensive evaluation using a membership function analysis, LS12 was identified as the cultivar with the best nutritional quality and antioxidant capacity. This study provides valuable insights into the nutritional attributes and antioxidant capacity of different leaf mustard cultivars and offers guidance for selecting varieties to promote a healthy diet.