Transcriptomic analysis reveals the defense mechanisms of citrus infested with Diaphorina citri

Huanglongbing(HLB) is a devastating disease that has led to an acute crisis for growers of citrus, one of the world's most important fruit crops. The phloem-feeding Asian citrus psyllid(ACP), Diaphorina citri, is the main pest at the new shoot stage and is the only natural vector of HLB pathogenic bacteria. Little is known about how plants perceive and defend themselves from this destructive pest. Here, we characterized changes in the expression of various genes in citrus plants that were continuously infested by D. citri for different durations(12, 24, and 48 h). A total of 5 219 differentially expressed genes(DEGs) and 643 common DEGs were identified across all time points. Several pathways related to defense were activated, such as peroxisome, alpha-linolenic acid metabolism, and phenylpropanoid and terpenoid biosynthesis, and some pathways related to growth and signal transduction were suppressed in response to D. citri infestation. The expression of genes including kinases(CML44, CIPK6, and XTH6), phytohormones(SAMT, LOX6, and NPR3), transcription factors(bHLH162, WRKY70, and WRKY40), and secondary metabolite synthesis-related genes(PAL, 4CL2, UGT74B1 and CYP82G1) was significantly altered in response to D. citri infestation. The findings of this study greatly enhance our understanding of the mechanisms underlying the defense response of citrus plants to D. citri infestation at the molecular level. Functional characterization of the candidate defense-related genes identified in this study will aid the molecular breeding of insect-resistant citrus varieties.

Detection of Citrus Psyllid Based on Improved YOLOX Model

[Objectives]The paper was to explore a faster and more accurate detection method for citrus psyllid to prevent and control yellow-shoot disease and inhibit its transmission.[Methods]We used an improved YOLOX based edge detection method for psyllid,added Convolutional Block Attention Module(CBAM)to the backbone network,and further extracted important features in the channel and space dimensions.The Cross Entropy Loss in the object loss was changed to Focal Loss to further reduce the missed detection rate.[Results]The algorithm described in the study fitted in with the detection platform of psyllid.The data set of psyllid was taken in Lianjiang Orange Garden,Zhanjiang City,Guangdong Province,deeply adapted to the actual needs of agricultural and rural development.Based on YOLOX model,the backbone network and loss function were improved to achieve a more excellent detection method of citrus psyllid.The AP value of 85.66%was obtained on the data set of citrus psyllid,which was 2.70%higher than that of the original model,and the detection accuracies were 8.61%,4.32%and 3.62%higher than that of YOLOv3,YOLOv4-Tiny and YOLOv5-s,respectively,which had been greatly improved.[Conclusions]The improved YOLOX model can better identify citrus psyllid,and the accuracy rate has been improved,laying a foundation for the subsequent real-time detection platform.

Metabolic Profiling in Banana Pseudo-Stem Reveals a Diverse Set of Bioactive Compounds with Potential Nutritional and Industrial Applications

Banana(Musa spp.)is an ancient and popular fruit plant with highly nutritious fruit.The pseudo-stem of banana represents on average 75%of the total dry mass but its valorization as a nutritional and industrial by-product is limited.Recent advances in metabolomics have paved the way to understand and evaluate the presence of diverse sets of metabolites in different plant parts.This study aimed at exploring the diversity of primary and secondary metabolites in the banana pseudo-stem.Hereby,we identified and quantified 373 metabolites from a diverse range of classes including,alkaloids,flavonoids,lipids,phenolic acids,amino acids and its derivatives,nucleotide and its derivatives,organic acids,lignans and coumarins,tannins,and terpene using the widely-targeted metabolomics approach.Banana pseudo-stem is enriched in metabolites for utilization in the food industry(L-lysine and L-tryptophan,L-glutamic acid,Phenylalanine,Palmitoleic acid,α-Linolenic acid,and Lauric acid,and Adenine)and pharmaceutical industry(Guanosine and Cimidahurinine,Bergapten,Coumarins,Procyanidin A2,Procyanidin B1,Procyanidin B3,Procyanidin B2,and Procyanidin B4,Asiatic acid).The metabolome of banana pseudo-stem with integration across multiomics data may provide the opportunity to exploit the rich metabolome of banana pseudo-stem for industrial and nutritional applications.

Efficient and transgene‑free genome editing in banana using a REG‑2 promoter-driven gene‑deletion system

The Streptococcus-derived CRISPR/Cas9 system can introduce precise and predictable modifications into the plant genome to obtain the desired traits.As one of the most advanced tools for editing crop genomes,the CRISPR/Cas9 system has been expanding rapidly and has been widely applied to determine gene function and improve agronomic traits in horticultural crops such as fruits and vegetables(Ma et al.2023).