TY - JOUR
T1 - Interactions among Fe2+, S2-, and Zn2+ tolerance, root anatomy, and radial oxygen loss in mangrove plants
AU - Cheng, Hao
AU - Chen, Dan Ting
AU - Tam, Nora Fung Yee
AU - Chen, Gui Zhu
AU - Li, Shi Yu
AU - Ye, Zhi Hong
N1 - Funding Information:
We sincerely thank Professor A.J.M. Baker (University of Melbourne, Australia, and University of Sheffield, UK) for improving this manuscript. We are also very grateful to Mr Chen Leifu, Mr Lin Zhenguang, Mr Wang Maoyi, Mr Yao Haixing, Ms Peng Xiaoyan and Ms Xiong Mingyu for their technical assistance. This work was financially supported by the National ‘863’ project of China (2007AA091703), National Natural Science Foundation of China (30570345, 41106103), Specialized Research Fund for the Doctoral Program of Higher Education of China (20100171110035), and the Areas of Excellence established under the RGC of the Hong Kong SAR (Project No. AoE/P-04/04).
PY - 2012/4
Y1 - 2012/4
N2 - Root anatomy, radial oxygen loss (ROL), and tolerances to ferrous (Fe 2+), sulphide (S2-), and zinc (Zn2+) ions were investigated in seedlings of eight species of mangrove, including three pioneer species, three rhizophoraceous and two landward semi-mangrove species. The results showed an interesting co-tolerance to Fe2+, S2-, and Zn2+. The three rhizophoraceous species (Bruguiera gymnorrhiza, Kandelia obovata and Rhizophora stylosa), which possessed the thickest lignified exodermis and the 'tightest barrier' in ROL spatial pattern, consistently exhibited the highest tolerance to Fe2+, S2-, and Zn 2+. B. gymnorrhiza could directly reduce ROL by increasing lignification within the exodermis. Such an induced barrier to ROL is a probable defence response to prevent further invasion and spread of toxins within plants. The data also indicated that, in B. gymnorrhiza, Fe2+ or S2-, or both, induced a lignified exodermis that delayed the entry of Zn2+ into the roots and thereby contributed to a higher tolerance to Zn2+. This study provides new evidence of exclusive strategies of mangrove seedling roots in dealing with contaminations. The information is also important in the selection and cultivation of tolerant species for the bioremediation of contaminated waters or soils.
AB - Root anatomy, radial oxygen loss (ROL), and tolerances to ferrous (Fe 2+), sulphide (S2-), and zinc (Zn2+) ions were investigated in seedlings of eight species of mangrove, including three pioneer species, three rhizophoraceous and two landward semi-mangrove species. The results showed an interesting co-tolerance to Fe2+, S2-, and Zn2+. The three rhizophoraceous species (Bruguiera gymnorrhiza, Kandelia obovata and Rhizophora stylosa), which possessed the thickest lignified exodermis and the 'tightest barrier' in ROL spatial pattern, consistently exhibited the highest tolerance to Fe2+, S2-, and Zn 2+. B. gymnorrhiza could directly reduce ROL by increasing lignification within the exodermis. Such an induced barrier to ROL is a probable defence response to prevent further invasion and spread of toxins within plants. The data also indicated that, in B. gymnorrhiza, Fe2+ or S2-, or both, induced a lignified exodermis that delayed the entry of Zn2+ into the roots and thereby contributed to a higher tolerance to Zn2+. This study provides new evidence of exclusive strategies of mangrove seedling roots in dealing with contaminations. The information is also important in the selection and cultivation of tolerant species for the bioremediation of contaminated waters or soils.
KW - apoplasmic barrier
KW - co-tolerance
KW - mangrove
KW - radial oxygen loss
KW - root anatomy
UR - http://www.scopus.com/inward/record.url?scp=84858337496&partnerID=8YFLogxK
U2 - 10.1093/jxb/err440
DO - 10.1093/jxb/err440
M3 - Article
C2 - 22268157
AN - SCOPUS:84858337496
SN - 0022-0957
VL - 63
SP - 2619
EP - 2630
JO - Journal of Experimental Botany
JF - Journal of Experimental Botany
IS - 7
ER -