(E)-Nerolidol is a volatile signal that induces defenses against insects and pathogens in tea plants

Plants release large amounts of volatile organic compounds(VOCs)in response to attackers.Several VOCs can serve as volatile signals to elicit defense responses in undamaged tissues and neighboring plants,but many questions about the ecological functions of VOCs remain unanswered.Tea plants are impacted by two harmful invaders,the piercing herbivore Empoasca(Matsumurasca)onukii Matsuda and the pathogen Colletotrichum fructicola.To determine the VOC signals in tea,we confirmed CsOPR3 as a marker gene and set up a rapid screening method based on a 1.51 kb CsOPR3 promoter fused with aβ-glucuronidase(GUS)reporter construct(OPR3p::GUS)in Arabidopsis.Using this screening system,a terpenoid volatile(E)-nerolidol was identified as a potent signal that elicits plant defenses.The early responses triggered by(E)-nerolidol included the activation of a mitogen-activated protein kinase and WRKY,an H2O2 burst,and the induction of jasmonic acid and abscisic acid signaling.The induced plants accumulated high levels of defenserelated chemicals,which possessed broad-spectrum anti-herbivore or anti-pathogen properties,and ultimately triggered resistance against Empoasca onukii and Colletotrichum fructicola in tea.We propose that these findings can supply an environmentally friendly management strategy for controlling an insect pest and a disease of tea plants.

Development and Application of Green Pest Control Technology in Tea Garden

A discussion on the necessity of green control of tea pests in tea gardens was conducted on the basis of the development process from traditional control, chemical control to green and ecological control. The connotation of green control in tea gardens was analyzed, and physical control and chemo-ecological control, biological control and agricultural control respectively were introduced. Besides, the rational selection and precise use of pesticides were proposed and current problems in the green control of tea gardens in China were introduced.

9,10-Anthraquinone contamination in tea processing using coal as heat source

9,10-Anthraquinone(AQ)is a contaminant with a potential carcinogenic risk and occurs in tea worldwide.The maximum residue limit(MRL)of AQ in tea set by the European Union(EU)is 0.02 mg/kg.The possible sources of AQ in tea processing and the main stages of its occurrence were investigated based on a modified AQ analytical method and gas chromatography-tandem mass spectrometry(GC-MS/MS)analysis.Compared with electricity as the heat source in green tea processing,AQ increased by 4.3 to 23.9 times in tea processing with coal as the heat source,far exceeding 0.02 mg/kg,while the AQ level in the environment tripled.The same trend was observed in oolong tea processing under coal heat.The steps with direct contact between tea leaves and fumes,such as fixation and drying,are considered as the main steps of AQ production in tea processing.The levels of AQ increased with the rising contact time,suggesting that high levels of AQ pollutant in tea may be derived from the fumes caused by coal and combustion.Fourty samples from different workshops with electricity or coal as heat sources were analyzed,ranged from 50.0%−85.0%and 5.0%−35.0%for detection and exceed rates of AQ.In addition,the maximum AQ content of 0.064 mg/kg was observed in the tea product with coal as the heat source,indicating that the high levels of AQ contamination in tea products are likely to be contributed by coal.

Inaugural Editorial

Many loved beverages worldwide are derived from plants.Some of the most important and popular examples of these beverage crops are tea,coffee,and cacao,which provide great economic value from source to consumption across the world.The buds and tender leaves of the tea plant(Camellia sinensis)can be used to make various tea products by specific processing or manufacture methods.The seeds(beans)of the coffee(Coffea arabica and C.canephora)and cacao(Theobroma cacao)trees once roasted create products with complex aromas and tastes loved by many on a daily basis.As the most popular non-alcoholic drinks in the world outside of pure water,they each contain an abundant mixture of specific secondary metabolites.These secondary metabolites not only give the beverage unique aroma,taste and flavor,they also have been correlated or directly shown through hundreds of clinical peer reviewed studies to benefit human health.These extensive studies have been reported and indicated that and tea,coffee,and cacao drinks are able to reduce the risk of memory disorders,Parkinson's disease,type-2 diabetes,cancer,and so much more.Many other crops have also been used for beverage making,such as cacti,coconut,etc.