Plants release an array of volatile chemicals into the air to communicate with other organisms in the environment. Insect attack triggers emission of herbivore-induced plant volatiles (HIPVs). How insect herbivores use these odors to plan their detoxification systems is vital for insect adaptation to environmental xenobiotics. Here we show that the larvae of Helicoverpa armigera (Hübner), a broadly polyphagous lepidopteran herbivore, have the capacity to use plant volatiles as cues to upregulate multiple detoxification systems, including cytochrome P450 monooxygenases (P450s), for detoxification of insecticides. Olfactory exposure of the fifth instars to two terpene volatiles limonene and nerolidol, and two green-leaf volatiles 2-heptanone and cis-3-hexenyl acetate significantly reduced larval susceptibility to the insecticide methomyl. However, larval pretreatment with piperonyl butoxide (PBO), a known P450 inhibitor, neutralized the effects of volatile exposure. Furthermore, larval exposure to the four plant volatiles enhanced activities of P450 enzymes in midguts and fatbodies, and upregulated expression of CYP6B2, CYP6B6 and CYP6B7, P450s involved in detoxification of the insecticide. Larval exposure to 2-heptanone and limonene volatiles also enhanced activities of glutathione-s-transferase and carboxylesterase. Our findings suggest that olfactory exposure to HIPVs enhances larval insecticide tolerance via induction of detoxification P450s.

Cherry (Prunus avium) has become an important economical fruit in China. In October 2020, a leaf spot disease was found on cherry in the orchard of Taizhou Academy of Agriculture Sciences, Zhejiang, China. The symptoms appeared as small, water-soaked spots on the leaves, which later became larger, dark brown, and necrotic lesions of 1 cm to 3 cm in width, 4 cm to 8 cm in length. Disease incidences of approximately 60% of the leaves were observed by sampling five locations. To isolate the causing agent, small fragments from five target symptomatic leaves were surface-sterilized with 1.0% sodium hypochlorite solution for 1 min and then rinsed three times with sterilized water. Afterwards the leaf fragments were air-dried, plated onto potato dextrose agar (PDA) medium, and incubated at 25 ℃ in the dark for 2 days. The pure cultures were obtained by transferring hyphal plug of 2 mm in diameter onto PDA, which followed single spore isolation. The colony morphology showed light to dark gray, cottony mycelium, with the underside of the culture became brownish after 7 days. Conidia (n = 28) were hyaline, smooth-walled, cylindrical, aseptate, broadly rounded ends, and average size around 3.84 × 12.82 μm (2.99 to 4.87 × 10.27 to 15.68 μm). Appressoria (n = 27) were mostly brown, ovoid and slightly irregular in shape, and average size around 8.04 × 9.68 μm (6.29 to 9.67 × 9.32 to 12.06 μm). Perithecia average size is 106.25 μm, textura angularis, thick-walled. Asci 26.35-49.18 × 5.00-12.03 μm (average size 37.44 × 7.80 μm, n = 17), unitunicate, thin-walled, clavate or cymbiform. Ascospores 13.69-20.93 × 3.86-6.69 μm (average size 16.00 × 5.42 μm, n = 30), one-celled, hyaline, one or two large guttulate at the centre, slightly rounded ends. The morphological characteristics matched well with previous descriptions of Colletotrichum species of C. gloeosporioides species complex, including C. fructicola (Prihastuti et al. 2009; Fu et al. 2019). The identity of two representative isolates (cf2-3 and cf4-4) from different leaves was confirmed by means of multi-locus gene sequencing. To this end, genomic DNA was extracted by the Plant Direct PCR kit (Vazyme Biotech Co., Ltd, China). Molecular identification was conducted by sequencing the internal transcribed spacer (ITS) rDNA region, partial glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene, partial actin (ACT) gene, partial beta-tubulin 2 gene (TUB2), and partial chitin synthase gene (CHS). The obtained sequences have been deposited in GenBank under accession numbers MW581851 and MW581852 (ITS), MW590586 and MW590587 (GAPDH), MW616561 and MW616562 (ACT), MW729380 and MW729381 (TUB2), MW729378 and MW729379 (CHS). The results of Basic Local Alignment Search Tool (BLAST) analysis revealed that the ITS, GAPDH, ACT, TUB2 and CHS sequences of both isolates matched with 100% identity to Colletotrichum fructicola culture collection sequences in GenBank database (JX010165, JX009998, JX009491, JX010405, and JX009866 respectively). These morphological characteristics and molecular analyses allowed the identification of the pathogen as C. fructicola. Koch's postulates were performed with healthy detached cherry leaves of cultivar namely 'HongMi' from Taizhou Academy of Agriculture Sciences. Surface-sterilized leaves were inoculated with five-day-old cultures of C. fructicola mycelial discs of 2 mm in diameter after being wounded with a needle or non-wounded. Control leaves were inoculated with discs of same size PDA agar. Treated leaves were incubated at 25 ℃ in the dark at high relative humidity. Anthracnose symptoms appeared within 3 days both on non-wounded and wounded inoculation approaches. Mock-inoculated controls remained asymptomatic. Biological repetitions were carried out three times. The fungus was reisolated from infected leaves and confirmed as C. fructicola following the methods described above. Until recently, it has been found that C. fructicola can infect tea, apple, pear, Pouteria campechiana in China (Fu et al. 2014; Li et al. 2013; Shi et al. 2018; Yang et al. 2020). To the best of our knowledge, this is the first report of C. fructicola on cherry in China.

The key role of soil quality improvement in achieving sustainable agricultural development based on highly intensive use of farmland is increasingly being recognized, as is the ponderance of suitable evaluation of the soil quality. The overarching goal of this study was to determine an accurate assessment framework by the comparison of the scoring function (linear and non-linear) and integration method (area and weighted additive), which integrally evaluates the soil quality of an eleven-year field fertilization experiment (including CK, no fertilizer; CF, conventional fertilization; SF, formulated fertilization; SFO, SF with organic fertilizer). Thirty-three properties, including eighteen physiochemical-related and fifteen biological-related properties, associated with soil functions were measured as potential soil quality indicators, and the soil multifunctionality (SMF) was applied to validate the soil quality indices (SQIs). Principal component analysis and relationship analysis were used with indicators sensitive to management to determine a minimum data set (MDS). The results showed that the electrical conductivity, large macroaggregate-associated total nitrogen, small macroaggregate-associated organic carbon, carbon fixation, and enzyme activities of phenol oxidase and cellulase were chosen as the MDS. All the SQIs were significantly correlated with the SMF (p < 0.05). The fertilization strategies affected most indicators in different ways, and the index developed using the non-linear function and weighted additive integration method (SQI-NL) had the best sensibility and discriminability. The SQI value with the SQI-NL-MDS method was higher following the fertilization treatments than that of no fertilizer (p < 0.05), and the treatment of the organic fertilizer had the highest SQI value (0.66). Soil quality evaluation in long-term fertilized farmland suggested that the soil quality constraints between treatments of synthetic and organic fertilizer are related to the soil functions of nutrient cycling and sustain biological activity due to their higher contribution rates to the SQI in the organic fertilizer treatment, which provides insights into ways to reduce the gap in soil quality. The framework method can provide an accurate quantitative tool for the evaluation of soil quality from the target indicators by bridging management objectives and field-level actions.

Background: Chrysanthemum virus B (CVB), a key member of the genus Carlavirus, family Betaflexiviridae, causes severe viral diseases in chrysanthemum (Chrysanthemum morifolium) plants worldwide. However, information on the mechanisms underlying the response of chrysanthemum plants to CVB is scant. Methods: Here, an integrated next-generation sequencing and comparative transcriptomic analysis of chrysanthemum leaves was conducted to explore the molecular response mechanisms of plants to a Chinese isolate of CVB (CVB-CN) at the molecular level. Results: In total, 4934 significant differentially expressed genes (SDEGs) were identified to respond to CVB-CN, of which 4097 were upregulated and 837 were downregulated. Gene ontology and functional classification showed that the majority of upregulated SDEGs were categorized into gene cohorts involved in plant hormone signal transduction, phenylpropanoid and flavonoid biosynthesis, and ribosome metabolism. Enrichment analysis demonstrated that ethylene pathway-related genes were significantly upregulated following CVB-CN infection, indicating a strong promotion of ethylene biosynthesis and signaling. Furthermore, disruption of the ethylene pathway in Nicotiana benthamiana, a model plant, using virus-induced gene silencing technology rendered them more susceptible to cysteine-rich protein of CVB-CN induced hypersensitive response, suggesting a crucial role of this pathway in response to CVB-CN infection. Conclusion: This study provides evidence that ethylene pathway has an essential role of plant in response to CVB and offers valuable insights into the defense mechanisms of chrysanthemum against Carlavirus.

Background: High-temperature stress (HTS) is one of the main environmental stresses that limit plant growth and crop production in agricultural systems. Maca (Lepidium meyenii) is an important high-altitude herbaceous plant adapted to a wide range of environmental stimuli such as cold, strong wind and UV-B exposure. However, it is an extremely HTS-sensitive plant species. Thus far, there is limited information about gene/protein regulation and signaling pathways related to the heat stress responses in maca. In this study, proteome profiles of maca seedlings exposed to HTS for 12 h were investigated using a tandem mass tag (TMT)-based proteomic approach.Results: In total, 6966 proteins were identified, of which 300 showed significant alterations in expression following HTS. Bioinformatics analyses indicated that protein processing in endoplasmic reticulum was the most significantly up-regulated metabolic pathway following HTS. Quantitative RT-PCR (qRT-PCR) analysis showed that the expression levels of 19 genes encoding proteins mapped to this pathway were significantly up-regulated under HTS. These results show that protein processing in the endoplasmic reticulum may play a crucial role in the responses of maca to HTS.Conclusions: Our proteomic data can be a good resource for functional proteomics of maca and our results may provide useful insights into the molecular response mechanisms underlying herbal plants to HTS.