Open AccessModerate salt treatment alleviates ultraviolet-B radiation caused impairment in poplar plants
Author(s) -
Xuan Ma,
Yongbin Ou,
Yue Gao,
Stanley Lutts,
Taotao Li,
Yang Wang,
Yongfu Chen,
Yimeng Sun,
Yi Yao
Publication year - 2016
Publication title -
scientific reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.24
H-Index - 213
ISSN - 2045-2322
DOI - 10.1038/srep32890
Subject(s) - salinity , proline , osmolyte , betaine , botany , phenylpropanoid , chemistry , horticulture , gene , biology , food science , biochemistry , biosynthesis , ecology , amino acid
The effects of moderate salinity on the responses of woody plants to UV-B radiation were investigated using two Populus species ( Populus alba and Populus russkii ). Under UV-B radiation, moderate salinity reduced the oxidation pressure in both species, as indicated by lower levels of cellular H 2 O 2 and membrane peroxidation, and weakened the inhibition of photochemical efficiency expressed by O-J-I-P changes. UV-B-induced DNA lesions in chloroplast and nucleus were alleviated by salinity, which could be explained by the higher expression levels of DNA repair system genes under UV-B&salt condition, such as the PHR, DDB2, and MutSα genes. The salt-induced increase in organic osmolytes proline and glycine betaine, afforded more efficient protection against UV-B radiation. Therefore moderate salinity induced cross-tolerance to UV-B stress in poplar plants. It is thus suggested that woody plants growing in moderate salted condition would be less affected by enhanced UV-B radiation than plants growing in the absence of salt. Our results also showed that UV-B signal genes in poplar plants PaCOP1 , PaSTO and PaSTH2 were quickly responding to UV-B radiation, but not to salt. The transcripts of PaHY5 and its downstream pathway genes ( PaCHS1 , PaCHS4 , PaFLS1 and PaFLS2 ) were differently up-regulated by these treatments, but the flavonoid compounds were not involved in the cross-tolerance since their concentration increased to the same extent in both UV-B and combined stresses.