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Hypoxia and bicarbonate could limit the expression of iron acquisition genes in Strategy I plants by affecting ethylene synthesis and signaling in different ways
Author(s) -
García María J.,
GarcíaMateo María J.,
Lucena Carlos,
Romera Francisco J.,
Rojas Carmen L.,
Alcántara Esteban,
PérezVicente Rafael
Publication year - 2014
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/ppl.12076
Subject(s) - chlorosis , bicarbonate , arabidopsis , ethylene , hypoxia (environmental) , gene , biology , gene expression , biochemistry , microbiology and biotechnology , mutant , chemistry , botany , endocrinology , organic chemistry , catalysis , oxygen
In a previous work, it was shown that bicarbonate (one of the most important factors causing Fe chlorosis in Strategy I plants) can limit the expression of several genes involved in Fe acquisition. Hypoxia is considered another important factor causing Fe chlorosis, mainly on calcareous soils. However, to date it is not known whether hypoxia aggravates Fe chlorosis by affecting bicarbonate concentration or by specific negative effects on Fe acquisition. Results found in this work show that hypoxia, generated by eliminating the aeration of the nutrient solution, can limit the expression of several Fe acquisition genes in Fe‐deficient Arabidopsis , cucumber and pea plants, like the genes for ferric reductases AtFRO2 , PsFRO1 and CsFRO1 ; iron transporters AtIRT1 , PsRIT1 and CsIRT1 ; H + ‐ ATPase CsHA1 ; and transcription factors AtFIT , AtbHLH38 , and AtbHLH39 . Interestingly, the limitation of the expression of Fe‐acquisition genes by hypoxia did not occur in the Arabidopsis ethylene constitutive mutant ctr1 , which suggests that the negative effect of hypoxia is related to ethylene, an hormone involved in the upregulation of Fe acquisition genes. As for hypoxia, results obtained by applying bicarbonate to the nutrient solution suggests that ethylene is also involved in its negative effect, since ACC (1‐aminocyclopropane‐1‐carboxylic acid; ethylene precursor) partially reversed the negative effect of bicarbonate on the expression of Fe acquisition genes. Taken together, the results obtained show that hypoxia and bicarbonate could induce Fe chlorosis by limiting the expression of Fe acquisition genes, probably because each factor negatively affects different steps of ethylene synthesis and/or signaling.