Identification of floral volatiles from Fagopyrum esculentum that attract Cotesia vestalis with potentially better biocontrol efficacy against Plutella xylostella.

BACKGROUND: Nectar plants provide extra nourishment for parasitoids, which can utilize floral volatiles to locate nectar-rich flowers. A promising strategy is to screen potential floral species based on the wasps' olfactory preferences for nectar sources, and to ensure their suitability for both natural enemies and targeted pests. Cotesia vestalis (Haliday) is a dominant parasitoid of the oligophagous pest Plutella xylostella, which poses a significant threat to cruciferous vegetables globally. However, the chemical cues in plant-parasitoid complexes mediating Cotesia vestalis to locate nectar food resources and the positive effect of nectar plants on the Cotesia vestalis population are poorly understood. RESULTS: The results showed that Fagopyrum esculentum was the most attractive plant that attracted Cotesia vestalis, not Plutella xylostella in 44 flowering plants from 19 families. 1,2-Diethyl benzene and 1,4-diethyl benzene, identified from the floral volatiles from F. esculentum in full bloom, were found to elicit dose-dependent electrophysiological responses and attract Cotesia vestalis adults, demonstrating their potential as semiochemicals. Moreover, the age-stage, two-sex life table revealed that feeding on nectar food increased the efficacy of Cotesia vestalis adults against Plutella xylostella. CONCLUSION: In summary, the findings provide insights into the chemical ecology of plant-parasitoid complexes and support the potential use of F. esculentum as insectary plants in habitat manipulation against Plutella xylostella by supplying natural nectar food for the Cotesia vestalis population. Our results suggest an attract and reward strategy based on an attractant for Cotesia vestalis to control Plutella xylostella, or the development of volatile-based artificial food for Cotesia vestalis. © 2023 Society of Chemical Industry.

The RpTOE1-RpFT Module Is Involved in Rejuvenation during Root-Based Vegetative Propagation in Robinia pseudoacacia.

Vegetative propagation is an important method of reproduction and rejuvenation in horticulture and forestry plants with a long lifespan. Although substantial juvenile clones have been obtained through the vegetative propagation of ornamental plants, the molecular factors that regulate rejuvenation during vegetative propagation are largely unknown. Here, root sprouting and root cutting of Robinia pseudoacacia were used as two vegetative propagation methods. From two consecutive years of transcriptome data from rejuvenated seedlings and mature trees, one gene module and one miRNA module were found to be specifically associated with rejuvenation during vegetative propagation through weighted gene co-expression network analysis (WGCNA). In the gene module, a transcription factor-encoding gene showed high expression during vegetative propagation, and it was subsequently named RpTOE1 through homology analysis. Heterologous overexpression of RpTOE1 in wild-type Arabidopsis and toe1 toe2 double mutants prolonged the juvenile phase. The qRT-PCR results predicted RpFT to be a downstream gene that was regulated by RpTOE1. Further investigation of the protein-DNA interactions using yeast one-hybrid, electrophoretic mobility shift, and dual luciferase reporter assays confirmed that RpTOE1 negatively regulated RpFT by binding directly to the TOE binding site (TBS)-like motif on its promoter. On the basis of these results, we showed that the high expression of RpTOE1 during vegetative propagation and its inhibition of RpFT played a key role in the phase reversal of R. pseudoacacia.

Lycium barbarum polysaccharide protects against osteonecrosis of femoral head via regulating Runx2 expression.

BACKGROUND: Osteonecrosis of femoral head (ONFH) is a pathological state caused by lack of blood supply in femoral head. This study aimed to explore the function of Lycium barbarum polysaccharide (LBP), an antioxidant agent extracted from L. barbarum, on ONFH. METHODS: Osteonecrosis rat model was generated using lipopolysaccharide (LPS) and methylprednisolone followed by examination of body weight, blood glucose, morphology, and BMSC osteoblast differentiation. The effect and underlying mechanism of LBP on the proliferation, apoptosis, and osteoblast differentiation of BMSC were determined with or without LPS or hypoxia treatment using CCK-8. Alizarin Red S staining, flow cytometry, and western blot, respectively. RESULT: LBP could protect against glucocorticoid-induced ONFH in rats, resulting in improved sparse trabecular bone, empty lacunae and bone cell coagulation. Moreover, LBP promoted the proliferation and osteoblast differentiation of bone mesenchymal-derived stem cells (BMSCs) in a dose-dependent manner. Furthermore, LBP enhanced osteoblast differentiation of BMSCs under hypoxia condition. Mechanistically, we found that LBP treatment enhanced Runx2 and ALP expression in BMSCs. LBP restored the expression of Runx2 and ALP under hypoxia, suggesting that LBP might be involved in regulating Runx2/ALP expression and contributed to osteoblast differentiation. Knockdown of Runx2 significantly inhibited BMSCs proliferation, while LBP treatment did not rescue the osteoblast differentiation ability of BMSCs with Runx2 knockdown. CONCLUSION: Our findings suggested that LBP protects against ONFH via regulating Runx2 expression, which could be utilized to treat patients suffering ONFH.

Selection and validation of reference genes for quantitative gene expression analyses in black locust (Robinia pseudoacacia L.) using real-time quantitative PCR.

Black locust (Robinia pseudoacacia L.) is an easy to raise, fast growing, medium-sized deciduous tree species highly tolerant to harsh eco-conditions, i.e., drought and harsh winters, and it is widely adaptable to sandy, loamy, and marshy soils. The basis for this adaptability remains to be investigated at the transcriptomic level using real-time quantitative PCR (qPCR). Selection of a reliable gene for the normalization of qPCR data is important for obtaining accurate results in gene expression. The goal of this study was to identify an appropriate reference gene from 12 candidate genes for gene expression analysis in black locust exposed to various stressors such as abscisic acid (ABA), NaCl, polyethylene glycol (PEG) and varying temperatures. In GeNorm and NormFinder analyses, ACT (actin) and GAPDH (glyceraldehyde-3-phosphate dehydrogenase) gene expression were the most stable in all conditions except heat stress, but in BestKeeper analysis, GAPDH and helicase gene expression were the most stable under NaCl and heat stress. In contrast, ACT and GAPDH were highest under abscisic acid (ABA), GAPDH and ßTUB (beta tubulin) under cold stress, and helicase and EF1α (elongation factor 1 alpha) under PEG stress. We found that the most stable reference gene combination for all conditions was ACT and GAPDH. Additionally, the expression pattern of NAC2 (a transcription factor) and BGL2 in different tissues and under different stress conditions was analyzed relative to ACT and GAPDH and UBQ (ubiquitin) the least stably expressed gene. NAC2 and BGL2 both had highest expression in flowers and pods under ABA stress at 48h. This study provides useful reference genes for future gene expression studies in black locust.