Inhibition of invasive plant Mikania micrantha rapid growth by host-specific rust (Puccinia spegazzinii).

Mikania micrantha Kunth is a fast-growing global invasive weed species that causes severe damage to natural ecosystems and very large economic losses of forest and crop production. Although Puccinia spegazzinii can effectively inhibit the growth of M. micrantha and is used as a biological control strain in many countries, the mechanism of inhibiting the growth of M. micrantha is not clear. Here, we used a combination of phenotypic, enzyme activity, transcriptomic, and metabolomic approaches to study the response of M. micrantha after infection by P. spegazzinii. In the early stages of rust infection, jasmonic acid (JA), jasmonoyl-isoleucine (JA-Ile), and salicylic acid (SA) levels in infected leaves were significantly lower than those in uninfected leaves. In teliospore initial and developed stages of P. spegazzinii, JA and JA-Ile levels substantially increased by more than 6 times, which resulted in a significant decrease in the accumulation of defense hormone SA in infected leaves of M. micrantha. The contents of plant growth-promoting hormones were significantly reduced in the infected plants as a result of substantial downregulation of the expression of key genes related to hormone biosynthesis. Furthermore, rust infection led to high levels of reactive oxygen species in chloroplasts and the destruction of chlorophyll structure, which also led to decreased photosynthetic gene expression, net photosynthetic rate, activity of Rubisco, and levels of important organic acids in the Calvin cycle. We hypothesized that after P. spegazzinii infection, JA or JA-Ile accumulation not only inhibited SA levels to promote rust infection and development, but also impeded the rapid growth of M. micrantha by affecting plant growth hormones, carbon, and nitrogen metabolic pathways.

A chromosome-level genome assembly of the beet armyworm Spodoptera exigua.

BACKGROUND: The beet armyworm Spodoptera exigua is a polyphagous caterpillar that causes serious damage to many species of crops and vegetables. To gain insight into how this polyphagous insect differs from less harmful oligophagous species, we generated a chromosome-level assembly and compared it to closely related species with the same or different feeding habits. RESULTS: Based on Illumina and Pacific Biosciences data and Hi-C technology, 425.6 Mb of genome sequences were anchored and oriented into 31 linkage groups, with an N50 length of 14.8 Mb. A total of 24,649 gene models were predicted, of which 97.4% were identified in the genome assembly. Chemosensory genes are vital for locating food: of the four main families, odorant-binding proteins, chemosensory proteins and olfactory receptors showed little difference, whereas gustatory receptors are greatly expanded in S. exigua. Examination of other polyphagous insects confirmed this difference from oligophagous congeners and further identified the bitter receptor subfamily as being particularly affected. CONCLUSION: Our high-quality genome sequence for beet armyworm identified a key expansion of the bitter gustatory receptor subfamily in this and other pests that differs crucially from more benign relatives and offers insight into the biology and possible future means of control for these economically important insects.

Genomic insights into longan evolution from a chromosome-level genome assembly and population genomics of longan accessions.

Longan (Dimocarpus longan) is a subtropical fruit best known for its nutritious fruit and regarded as a precious tonic and traditional medicine since ancient times. High-quality chromosome-scale genome assembly is valuable for functional genomic study and genetic improvement of longan. Here, we report a chromosome-level reference genome sequence for longan cultivar JDB with an assembled genome of 455.5 Mb in size anchored to fifteen chromosomes, representing a significant improvement of contiguity (contig N50 = 12.1 Mb, scaffold N50 = 29.5 Mb) over a previous draft assembly. A total of 40 420 protein-coding genes were predicted in D. longan genome. Synteny analysis suggests longan shares the widespread gamma event with core eudicots, but has no other whole genome duplications. Comparative genomics showed that D. longan genome experienced significant expansions of gene families related to phenylpropanoid biosynthesis and UDP-glucosyltransferase. Deep genome sequencing analysis of longan cultivars identified longan biogeography as a major contributing factor for genetic diversity, and revealed a clear population admixture and introgression among cultivars of different geographic origins, postulating a likely migration trajectory of longan overall confirmed by existing historical records. Finally, genome-wide association studies (GWAS) of longan cultivars identified quantitative trait loci (QTL) for six different fruit quality traits and revealed a shared QTL containing three genes for total soluble solid and seed weight. The chromosome-level reference genome assembly, annotation and population genetic resource for D. longan will facilitate the molecular studies and breeding of desirable longan cultivars in the future.

Influence of Supplemental Protein on the Life Expectancy and Reproduction of the Chinese Citrus Fruit Fly, Bactrocera minax (Enderlein) (Tetradacus minax) (Diptera: Tephritidae).

Bactrocera minax (Enderlein) (Diptera: Tephritidae) is a major citrus pest in China, whose artificial rearing technology of the adult is not well documented to date. In this study, we tried to determine if supplementing proteins to the adult diet could result in the enhancement of some fitness parameters of B. minax. Four feeds with varying protein source were provided as F0 (water), F1 (sucrose), F2 (sucrose + yeast), and F3 (sucrose + peptone). F0 and F1 being the control, F2 and F3 were protein food types. The results showed that adults fed by F2 and F3 lived longer with 40.1 d and 32.8 d, respectively, had reduced death rates (death peaks were delayed for 5.6 d and 4.1 d, respectively), increased mating frequencies (8.1 and 5.3 per females, 4.7 and 7.3 per males, respectively), and longer mating durations (with 42 d and 34 d). In addition, females recorded an increased adult ovary development, more egg load (with 94.8 and 77.3 brood eggs per ovary) and to greater oviposition rates of 63.2 eggs/female and 19.3 eggs/female. Based on our results, protein supplements enhanced B. minax survival, mating, and fecundity. This study does not only provide basic knowledge to implement artificial rearing of B. minax, but also deepens our understanding on its physiology that could be used to enhance the management of the pest.

[Summary of professor YANG Jun's experience for intractable facial paralysis].

Professor YANG Jun's experience of diagnosis and treatment for intractable facial paralysis is introduced. Professor YANG focuses on the thinking model that combines TCM, western medicine and acupuncture, and adopts the differentiation system that combines disease differentiation, syndrome differentiation and meridian differentiation; he adopts the treatment integrates etiological treatment, overall regulation, symptomatic treatment as well as acupuncture, moxibustion, medication and flash cupping. The acupoints of yangming meridians are mostly selected, and acupoints of governor vessel such as Dazhui (GV 14) and Jinsuo (GV 8) are highly valued. The multiple-needles shallow-penetration-insertion twirling lifting and thrusting technique are mostly adopted to achieve slow and mild acupuncture sensation; in addition, the facial muscles are pulled up with mechanics action. The intensive stimulation with electroacupuncture is recommended at Qianzheng (Extra), Yifeng (TE 17) and Yangbai (GB 14), which is given two or three treatments per week.