Mangrove ecosystem plays a vital role of ecological protection as a major primary producer in tropical and subtropic estuaries. Meanwhile, mangrove is a fragile ecosystem threatened by global climate change, human activities and anthropogenic contaminants.  

Recently, Prof. WANG Youshao's group from South China Sea Institute of Oceanology(SCSIO) of the Chinese Academy of Sciences explored the functions of lignin and suberin on metal detoxification in mangroves. They illustrated how lignin and suberin deposited within in the exodermal cell walls by scanning electron microscopy, fluorescence microscopy and GC-MS. The results showed that rhizophoraceous mangroves often exhibited a thick exodermis together with high lignin/suberin deposition. Moreover, the mangroves which possessed more extensive lignification/suberization within the exodermis appeared to exhibit higher metal tolerance. Because, the lignified/suberized exodermis would delayed the entry of metals into the roots, and thereby mitigated the harm to plants. 

This is the first time that the differences of lignin/suberin deposition within the exodermis and metal tolerance between pioneer and rhizophoraceous mangroves have been explored, proposing new evidence of structural adaptive strategy on metal detoxification. 

This research was supported by the National Natural Science Foundation of China (No. 41106103, 41076070, 41176101), and the National Science & Technology Pillar Program in the "Eleventh Five-year Plan" (No. 2012BAC07B0402). 

The study entitled “Metal (Pb, Zn and Cu) uptake and tolerance by mangroves in relation to root anatomy and lignification/suberization” has been published in Tree physiology.