Heme oxygenase is involved in cobalt chloride-induced lateral root development in tomato.
In animals, heme oxygenase (HO), a rate-limiting enzyme responsible for carbon monoxide (CO) production, was regarded as a protective system maintaining cellular homeostasis. It was also established that metal ions are powerful HO-inducing agents and cobalt chloride (CoCl(2)) was the first metal ion identified with an inducing property. Previous study suggests that CoCl(2) stimulates adventitious root formation in tomato and cucumber cuttings. In this test, we discover that both CoCl(2) and an inducer of HO-1, hemin, could lead to the promotion of lateral root development, as well as the induction of HO-1 protein expression, HO activity, or LeHO-1/2 transcripts, in lateral root initiation zone of tomato seedlings. The effect is specific for HO since the potent HO-1 inhibitor zinc protoporphyrin IX (ZnPPIX) blocked the above actions of CoCl(2), and the inhibitory effect was reversed partially when 50% CO aqueous solution was added. However, the addition of ascorbic acid (AsA), a well-known antioxidant, exhibited no obvious effect on lateral root formation. Molecular evidence further showed that CoCl(2)-induced the up-regulation of target genes responsible for lateral root formation, including LeCDKA1, LeCYCA2;1, and LeCYCA3;1, was suppressed differentially by ZnPPIX. And these decreases were reversed further by the addition of CO. All together, these results suggest a novel role for HO in the CoCl(2)-induced tomato lateral root formation.
Department of Biochemistry and Molecular Biology, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
Sheng
S
Xu
Bo
B
Zhang
Ze-Yu
ZY
Cao
Teng-Fang
TF
Ling
Wen-Biao
WB
Shen
D001205:Ascorbic Acid / Q000494:pharmacology; D015153:Blotting, Western; D003035:Cobalt / Q000494:pharmacology*; D006419:Heme Oxygenase (Decyclizing) / Q000235:genetics / Q000378:metabolism*; D018551:Solanum lycopersicum / Q000187:drug effects* / Q000201:enzymology* / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects* / Q000201:enzymology* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D036226:Seedlings / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism
D010940:Plant Proteins; D003035:Cobalt; D006419:Heme Oxygenase (Decyclizing); C018021:cobaltous chloride; D001205:Ascorbic Acid