Diel O₂ dynamics in partially and completely submerged deepwater rice: leaf gas films enhance internodal O₂ status, influence gene expression, and accelerate stem elongation for ‘snorkelling’ during submergence

TY - JOUR

T1 - Diel O2 dynamics in partially and completely submerged deepwater rice

T2 - leaf gas films enhance internodal O2 status, influence gene expression, and accelerate stem elongation for ‘snorkelling’ during submergence

AU - Mori, Yoshinao

AU - Kurokawa, Yusuke

AU - Koike, Masaya

AU - Malik, Al Imran

AU - Colmer, Timothy David

AU - Ashikari, Motoyuki

AU - Pedersen, Ole

AU - Nagai, Keisuke

PY - 2019/5/1

Y1 - 2019/5/1

N2 - Deepwater rice has a remarkable shoot elongation response to partial submergence. Shoot elongation to maintain air-contact enables ‘snorkelling’ of O2 to submerged organs. Previous research has focused on partial submergence of deepwater rice. We tested the hypothesis that leaf gas films enhance internode O2 status and stem elongation of deepwater rice when completely submerged. Diel patterns of O2 partial pressure (pO2) were measured in internodes of deepwater rice when partially or completely submerged, and with or without gas films on leaves, for the completely submerged plants. We also took measurements for paddy rice. Deepwater rice elongated during complete submergence and the shoot tops emerged. Leaf gas films improved O2 entry during the night, preventing anoxia in stems, which is of importance for elongation of the submerged shoots. Expressions of O2 deprivation inducible genes were upregulated in completely submerged plants during the night, and more so when gas films were removed from the leaves. Diel O2 dynamics showed similar patterns in paddy and deepwater rice. We demonstrated that shoot tops in air enabled ‘snorkelling’ and increased O2 in internodes of both rice ecotypes; however, ‘snorkelling’ was achieved only by rapid shoot elongation by deepwater rice, but not by paddy rice.

AB - Deepwater rice has a remarkable shoot elongation response to partial submergence. Shoot elongation to maintain air-contact enables ‘snorkelling’ of O2 to submerged organs. Previous research has focused on partial submergence of deepwater rice. We tested the hypothesis that leaf gas films enhance internode O2 status and stem elongation of deepwater rice when completely submerged. Diel patterns of O2 partial pressure (pO2) were measured in internodes of deepwater rice when partially or completely submerged, and with or without gas films on leaves, for the completely submerged plants. We also took measurements for paddy rice. Deepwater rice elongated during complete submergence and the shoot tops emerged. Leaf gas films improved O2 entry during the night, preventing anoxia in stems, which is of importance for elongation of the submerged shoots. Expressions of O2 deprivation inducible genes were upregulated in completely submerged plants during the night, and more so when gas films were removed from the leaves. Diel O2 dynamics showed similar patterns in paddy and deepwater rice. We demonstrated that shoot tops in air enabled ‘snorkelling’ and increased O2 in internodes of both rice ecotypes; however, ‘snorkelling’ was achieved only by rapid shoot elongation by deepwater rice, but not by paddy rice.

U2 - 10.1093/pcp/pcz009

DO - 10.1093/pcp/pcz009

M3 - Journal article

C2 - 30668838

SN - 0032-0781

VL - 60

SP - 973

EP - 985

JO - Plant and Cell Physiology

JF - Plant and Cell Physiology

IS - 5

ER -