TY - JOUR
T1 - OsFRDL1 expressed in nodes is required for distribution of iron to grains in rice
AU - Yokosho, Kengo
AU - Yamaji, Naoki
AU - Ma, Jian Feng
N1 - Publisher Copyright:
© The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2016/10/1
Y1 - 2016/10/1
N2 - Iron (Fe) is essential for plant growth and development, but the molecular mechanisms underlying its distribution to different organs are poorly understood. We found that OsFRDL1 (FERRIC REDUCTASE DEFECTIVE LIKE 1), a plasma membrane-localized transporter for citrate, was highly expressed in the upper nodes of rice at the reproductive growth stage. OsFRDL1 was expressed in most cells of enlarged vascular bundles, diffuse vascular bundles, and the interjacent parenchyma cell bridges of uppermost node I, as well as vascular tissues of the leaf blade, leaf sheath, peduncle, rachis, husk, and stamen. Knockout of OsFRDL1 decreased pollen viability and grain fertility when grown in a paddy field. Iron was deposited in the parenchyma cell bridges, a few of the cell layers of the parenchyma tissues outside of the bundle sheath of enlarged vascular bundles in node I in both the wild-type rice and osfrdl1 mutant, but the mutant accumulated more Fe than the wild-type rice in this area. A stem-fed experiment with stable isotope 57Fe showed that the distribution of Fe in the anther and panicle decreased in the knockout line, but that in the flag leaf it increased compared with the wild-type rice. Taken together, our results show that OsFRDL1 expressed in the upper nodes is required for the distribution of Fe in the panicles through solubilizing Fe deposited in the apoplastic part of nodes in rice.
AB - Iron (Fe) is essential for plant growth and development, but the molecular mechanisms underlying its distribution to different organs are poorly understood. We found that OsFRDL1 (FERRIC REDUCTASE DEFECTIVE LIKE 1), a plasma membrane-localized transporter for citrate, was highly expressed in the upper nodes of rice at the reproductive growth stage. OsFRDL1 was expressed in most cells of enlarged vascular bundles, diffuse vascular bundles, and the interjacent parenchyma cell bridges of uppermost node I, as well as vascular tissues of the leaf blade, leaf sheath, peduncle, rachis, husk, and stamen. Knockout of OsFRDL1 decreased pollen viability and grain fertility when grown in a paddy field. Iron was deposited in the parenchyma cell bridges, a few of the cell layers of the parenchyma tissues outside of the bundle sheath of enlarged vascular bundles in node I in both the wild-type rice and osfrdl1 mutant, but the mutant accumulated more Fe than the wild-type rice in this area. A stem-fed experiment with stable isotope 57Fe showed that the distribution of Fe in the anther and panicle decreased in the knockout line, but that in the flag leaf it increased compared with the wild-type rice. Taken together, our results show that OsFRDL1 expressed in the upper nodes is required for the distribution of Fe in the panicles through solubilizing Fe deposited in the apoplastic part of nodes in rice.
KW - 57Fe distribution
KW - Apoplastic Fe
KW - citrate efflux
KW - node
KW - rice
KW - transporter
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U2 - 10.1093/jxb/erw314
DO - 10.1093/jxb/erw314
M3 - Article
C2 - 27555544
AN - SCOPUS:84991401489
VL - 67
SP - 5485
EP - 5494
JO - Journal of Experimental Botany
JF - Journal of Experimental Botany
SN - 0022-0957
IS - 18
ER -