Behavioral responses of Platycladus orientalis plant volatiles to Phloeosinus aubei by GC-MS and HS-GC-IMS for discrimination of different invasive severity

Exogenous ABA promotes resistance to Sitobion avenae (Fabricius) in rice seedlings

BACKGROUND

Over the course of evolution, plants have developed various sophisticated defense mechanisms to resist pests and diseases. The phytohormone abscisic acid (ABA) has an important role in the growth and development of plants and confers tolerance to selected abiotic stressors, such as drought. Previous studies have shown that ABA promotes the deposit of callose in response to piercing/sucking insect pests. The English grain aphid, Sitobion avenae Fabricius, causes huge losses in rice and is especially harmful to rice seedlings.

RESULTS

Exogenous ABA promoted growth and reduced the feeding behavior of S. avenae nymphs in rice. Our results suggested that enhanced trichome density and increased expression of related genes may be associated with rice resistance to aphids. An analysis of volatiles revealed the production of seven compounds associated with pest resistance.

CONCLUSION

These results indicate that ABA reduces aphid feeding in rice. Our findings provide a basis for understanding ABA-mediated defense responses in rice and provide insights on more environmentally-friendly approaches to control. © 2024 Society of Chemical Industry.

Challenges and applications of volatile organic compounds monitoring technology in plant disease diagnosis

Biotic and abiotic stresses are well known to increase the emission of volatile organic compounds (VOCs) from plants. The analysis of VOCs emissions from plants enables timely diagnostic of plant diseases, which is critical for prompting sustainable agriculture. Previous studies have predominantly focused on the utilization of commercially available devices, such as electronic noses, for diagnosing plant diseases. However, recent advancements in nanomaterials research have significantly contributed to the development of novel VOCs sensors featuring exceptional sensitivity and selectivity. This comprehensive review presents a systematic analysis of VOCs monitoring technologies for plant diseases diagnosis, providing insights into their distinct advantages and limitations. Special emphasis is placed on custom-made VOCs sensors, with detailed discussions on their design, working principles, and detection performance. It is noteworthy that the application of VOCs monitoring technologies in the diagnostic process of plant diseases is still in its emerging stage, and several critical challenges demand attention and improvement. Specifically, the identification of specific stress factors using a single VOC sensor remains a formidable task, while environmental factors like humidity can potentially interfere with sensor readings, leading to inaccuracies. Future advancements should primarily focus on addressing these challenges to enhance the overall efficacy and reliability of VOCs monitoring technologies in the field of plant disease diagnosis.

Chemotaxonomic Variation in Volatile Component Contents in Ancient Platycladus orientalis Leaves with Different Tree Ages in Huangdi Mausoleum

To gain insight into the differences in the composition and volatile components content in ancient Platycladus orientalis leaves with different tree ages in Huangdi Mausoleum, the volatile components were identified by headspace solid-phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME-GC-MS) method. The volatile components were statistically analyzed by orthogonal partial least squares discriminant analysis and hierarchical cluster analysis, and the characteristic volatile components were screened. The results exhibited that a total of 72 volatile components were isolated and identified in 19 ancient Platycladus orientalis leaves with different tree ages, and 14 common volatile components were screened. Among them, the contents of α-pinene (6.40-16.76%), sabinene (1.11-7.29%), 3-carene (1.14-15.12%), terpinolene (2.17-4.95%), caryophyllene (8.04-13.53%), α-caryophyllene (7.34-14.41%), germacrene D (5.27-12.13%), (+)-Cedrol (2.34-11.30%) and α-terpinyl acetate (1.29-25.68%) were relatively higher (>1%), accounting for 83.40-87.61% of the total volatile components. Nineteen ancient Platycladus orientalis trees were clustered into three groups through the HCA method based on the 14 common volatile components content. Combined with the results of OPLS-DA analysis, (+)-cedrol, germacrene D, α-caryophyllene, α-terpinyl acetate, caryophyllene, β-myrcene, β-elemene and epiglobulol were the differential volatile components to distinguish ancient Platycladus orientalis with different tree ages. The results revealed that the composition of the volatile components in ancient Platycladus orientalis leaves with different tree ages was different, showing different aroma characteristics, which provided a theoretical reference for the differential development and application of volatile components in ancient Platycladus orientalis leaves.