Difference of proteomics vernalization-induced in bolting and flowering transitions of Beta vulgaris

The Dynamic Accumulation Rules of Chemical Components during the Medicine Formation Period of Angelica sinensis and Chemometric Classifying Analysis for Different Bolting Times Using ATR-FTIR

The dried roots of the perennial herb Angelica sinensis (Oliv.) Diels (AS) are commonly used as medicinal and edible resources. In commercial planting, early bolting and flowering (EB) of ca. 60% in the medicine formation period reduces root yield and quality, becoming a significant bottleneck in agricultural production. In the cultivation process, summer bolting (SB) occurs from June to July, and autumn bolting (AB) occurs in September. The AB root is often mistaken for the AS root due to its similar morphological characteristics. Few studies have involved whether the root of AB could be used as herbal medicine. This study explored and compared the accumulation dynamics of primary and secondary metabolites in AS and EB roots during the vegetative growth stage (from May to September) by light microscopy, ultraviolet spectrometry, and HPLC methods. Under a microscope, the amount of free starch granules and oil chamber in the AS root increased. On the contrary, they decreased further from EB-Jul to EB-Sep. By comparison, the wall of the xylem vessel was slightly thickened and stacked, and the cell walls of parenchyma and root cortex tissue were thickened in the EB root. Early underground bolting reduces soluble sugar, soluble protein, free amino acids, total C element, total N element, ferulic acid, and ligustilide accumulation, accompanied by the lignification of the root during the vegetative growth stage. Furthermore, a total of 55 root samples from different bolting types of AS root (29 samples), SB root (14 samples), and AB root (12 samples) were collected from Gansu Province during the harvesting period (October). The later the bolting occurred, the less difference there was between unbolted and bolted roots in terms of morphological appearance and efficacy components. Fourier transform infrared spectroscopy with the attenuated total reflection mode (ATR-FTIR) provides a "holistic" spectroscopic fingerprinting of all compositions in the tested sample. The ATR-FTIR spectrum of the AB root was similar to that of the AS root. However, the number and location of absorption peaks in the spectra of SB were different, and only one strong absorption peak at 1021 cm-1 was regarded as the characteristic peak of C-O stretching vibration in lignin. The ATR-FTIR spectra can be effectively differentiated based on their various characteristics using orthogonal partial least squares discrimination analysis (OPLS-DA). Results were assessed using multiple statistical techniques, including Spearman's correlation, principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), and OPLS-DA. Among these methods, the ATR-FTIR data demonstrated the most effective outcomes in differentiating between viable and non-viable roots for their application in herbal medicine. Essential substances are ferulic acid and flavonoid, which are much more abundant in the AB root. It provides a material basis for the pharmacological action of the AB roots and a theoretical basis for improving their availability.

Identification of the Genes Encoding B3 Domain-Containing Proteins Related to Vernalization of Beta vulgaris

Vernalization is the process of exposure to low temperatures, which is crucial for the transition from vegetative to reproductive growth of plants. In this study, the global landscape vernalization-related mRNAs and long noncoding RNAs (lncRNAs) were identified in Beta vulgaris. A total of 22,159 differentially expressed mRNAs and 4418 differentially expressed lncRNAs were uncovered between the vernalized and nonvernalized samples. Various regulatory proteins, such as zinc finger CCCH domain-containing proteins, F-box proteins, flowering-time-related proteins FY and FPA, PHD finger protein EHD3 and B3 domain proteins were identified. Intriguingly, a novel vernalization-related lncRNA-mRNA target-gene co-expression regulatory network and the candidate vernalization genes, VRN1, VRN1-like, VAL1 and VAL2, encoding B3 domain-containing proteins were also unveiled. The results of this study pave the way for further illumination of the molecular mechanisms underlying the vernalization of B. vulgaris.

Genome-wide identification of the KNOTTED HOMEOBOX gene family and their involvement in stalk development in flowering Chinese cabbage

Gibberellin and cytokinin synergistically regulate the stalk development in flowering Chinese cabbage. KNOX proteins were reported to function as important regulators of the shoot apex to promote meristem activity by synchronously inducing CTK and suppressing GA biosynthesis, while their regulatory mechanism in the bolting and flowering is unknown. In this study, 9 BcKNOX genes were identified and mapped unevenly on 6 out of 10 flowering Chinese cabbage chromosomes. The BcKNOXs were divided into three subfamilies on the basis of sequences and gene structure. The proteins contain four conserved domains except for BcKNATM. Three BcKNOX TFs (BcKNOX1, BcKNOX3, and BcKNOX5) displayed high transcription levels on tested tissues at various stages. The major part of BcKNOX genes showed preferential expression patterns in response to low-temperature, zeatin (ZT), and GA₃ treatment, indicating that they were involved in bud differentiation and bolting. BcKNOX1 and BcKNOX5 showed high correlation level with gibberellins synthetase, and CTK metabolic genes. BcKONX1 also showed high correlation coefficients within BcRGA1 and BcRGL1 which are negative regulators of GA signaling. In addition, BcKNOX1 interacted with BcRGA1 and BcRGL1, as confirmed by yeast two-hybrid (Y2H) and biomolecular fluorescence complementation assay (BiFC). This analysis has provided useful foundation for the future functional roles' analysis of flowering Chinese cabbage KNOX genes.

Comparative proteomic analysis on chloroplast proteins provides new insights into the effects of low temperature in sugar beet

BACKGROUND

Low temperature, which is one of the main environmental factors that limits geographical distribution and sucrose yield, is a common abiotic stress during the growth and development of sugar beet. As a regulatory hub of plant response to abiotic stress, activity in the chloroplasts is related to many molecular and physiological processes, particularly in response to low temperature stress.

RESULTS

The contents of chlorophyll (Chl) and malondialdehyde (MDA), relative electrical conductivity (REL), and superoxide dismutase (SOD) activity were measured. The results showed that sugar beet could manage low temperature stress by regulating the levels of Chl, REL and MDA, and the activity of SOD. The physiological responses indicated that sugar beets respond positively to low temperature treatments and are not significantly damaged. Moreover, to determine the precise time to response low temperature in sugar beet, well-known abiotic stresses-responsive transcript factor family, namely DEHYDRATION RESPONSIVE ELEMENT BINDING PROTEIN (DREB), was selected as the marker gene. The results of phylogenetic analyses showed that BvDREBA1 and BvDREBA4 were in the same branch as the cold- and drought-responsive AtDREB gene. In addition, the expression of BvDREBs reached its maximum level at 24 h after low temperature by RNA-Seq and qRT-PCR analysis. Furthermore, the changes in chloroplast proteome after low temperature at 24 h were detected using a label-free technique. A total of 416 differentially expressed proteins were identified. GO enrichment analysis showed that 16 GO terms were significantly enriched, particularly chloroplast stroma, chloroplast envelope, and chloroplast thylakoid membrane. It is notable that the transport of photosynthetic proteins (BvLTD and BvTOC100), the formation of starch granules (BvPU1, BvISA3, and BvGWD3) and the scavenging of reactive oxygen species (BvCu/Zn-SOD, BvCAT, BvPrx, and BvTrx) were the pathways used by sugar beets to respond to low temperatures at an early stage.

CONCLUSIONS

These results provide a preliminarily analysis of how chloroplasts of sugar beet respond to low temperature stress at the translational level and provide a theoretical basis for breeding low temperature resistant varieties of sugar beet.