Leaf miner-induced morphological, physiological and molecular changes in mangrove plant Avicennia marina (Forsk.) Vierh.
Avicennia marina (Forsk.) Vierh is a widespread mangrove species along the southeast coasts of China. Recently, the outbreak of herbivorous insect, Phyllocnistis citrella Stainton, a leaf miner, have impacted on the growth of A. marina. Little is reported about the responses of A. marina to leaf miner infection at the biochemical, physiological and molecular levels. Here, we reported the responses of A. marina to leaf miner infection from the aspects of leaf structure, photosynthesis, and antioxidant system and miner responsive genes expression. A. marina leaves attacked by the leaf miner exhibited significant decreases in chlorophyll, carbon and nitrogen contents, as well as a decreased photosynthetic rate. Scanning and transmission electron microscopic observations revealed that the leaf miner only invaded the upper epidermis and destroyed the epidermal cell, which lead to the exposure of salt glands. In addition, the chloroplasts of mined leaves (ML) were swollen and the thylakoids degraded. The maximal net photosynthetic rate, stomatal conductance (Gs), carboxylation efficiency (CE), dark respiration (Rd), light respiration (Rp) and quantum yields (AQE) significantly decreased in the ML, whereas the light saturation point (Lsp), light compensation point (Lcp), water loss and CO2 compensation point (Г) increased in the ML. Moreover, chlorophyll fluorescence features also had been changed by leaf miner attacks. Interestingly, higher generation rate of O2ˉ· and lower antioxidant enzyme expression in the mined portion (MP) were found; on the contrary, higher H2O2 level and higher antioxidant enzyme expression in the non-mined portion (NMP) were revealed, implying that the NMP may be able to sense that the leaf miner attacks had happened in the MP of the A. marina leaf via H2O2 signaling. Besides, the protein expression of glutathione S-transferase (GST) and the glutathione (GSH) content were increased in the ML. In addition, insect resistance-related gene expression such as chitinase 3, RAR1, topless and PIF3 had significantly increased in the ML. Taken together, our data suggest that leaf miners could significantly affect leaf structure, photosynthesis, the antioxidant system and miner responsive gene expression in A. marina leaves.
Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, P.R. China.|State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi, P.R. China.
Juan
J
Chen
Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, P.R. China.
Zhi-Jun
ZJ
Shen
Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, P.R. China.|National Marine Environmental Monitoring Center, State Oceanic Administration, Dalian, China.
Wei-Zhi
WZ
Lu
Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, P.R. China.
Xiang
X
Liu
Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, P.R. China.
Fei-Hua
FH
Wu
Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, P.R. China.
Gui-Feng
GF
Gao
Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, P.R. China.
Yi-Ling
YL
Liu
Institute of Zoology, Chinese Academy of Sciences, Beijing, P.R. China.
Chun-Sheng
CS
Wu
Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, P.R. China.
Chong-Ling
CL
Yan
Guangxi Mangrove Research Center, Beihai, Guangxi, China.
Hang-Qing
HQ
Fan
Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, P.R. China.
Yi-Hui
YH
Zhang
Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, P.R. China.
Hai-Lei
HL
Zheng
Chung-Jui
CJ
Tsai
D000818:Animals; D000898:Antibiosis; D000975:Antioxidants / Q000378:metabolism; D032407:Avicennia / Q000033:anatomy & histology* / Q000235:genetics / Q000502:physiology*; D020387:Food Chain; D015870:Gene Expression; D060434:Herbivory; D007814:Larva / Q000502:physiology; D009036:Moths / Q000254:growth & development / Q000502:physiology*; D010788:Photosynthesis; D018515:Plant Leaves / Q000033:anatomy & histology / Q000502:physiology; D010940:Plant Proteins / Q000378:metabolism
D000975:Antioxidants; D010940:Plant Proteins
antioxidant enzymes; Avicennia marina; leaf miner; leaf structure; photosynthesis