Rice acclimation to soil flooding: low concentrations of organic acids can trigger a barrier to radial oxygen loss in roots

TY - JOUR

T1 - Rice acclimation to soil flooding

T2 - low concentrations of organic acids can trigger a barrier to radial oxygen loss in roots

AU - Colmer, Timothy David

AU - Kotula, Lukasz

AU - Malik, Al Imran

AU - Takahashi, Hirokazu

AU - Konnerup, Dennis

AU - Nakazono, Mikio

AU - Pedersen, Ole

N1 - This article is protected by copyright. All rights reserved.

PY - 2019/7

Y1 - 2019/7

N2 - Waterlogged soils contain monocarboxylic acids produced by anaerobic microorganisms. These “organic acids” can accumulate to phytotoxic levels and promote development of a barrier to radial O2 loss (ROL) in roots of some wetland species. Environmental cues triggering root ROL barrier induction, a feature that together with tissue gas-filled porosity facilitates internal aeration, are important to elucidate for knowledge of plant stress physiology. We tested the hypothesis that comparatively low, non-toxic, concentrations of acetic, propionic, butyric, and/or hexanoic acids might induce root ROL barrier formation in rice. Each organic acid, individually, triggered the ROL barrier in roots but with no effect (acetic or butyric acids) or with only slight effects (propionic or hexanoic acids) on root extension. Transcripts of four genes related to suberin biosynthesis were increased by some of the organic acid treatments. Respiration in root tissues was not, or moderately, inhibited. Beyond a narrow concentration range, however, respiration declined exponentially and the order (least to greatest) for EC50 (effective concentration for 50% inhibition) was butyric, propionic, acetic, then hexanoic acid. An understanding of the environmental cue for root ROL barrier induction should enhance future work to elucidate the molecular regulation of this root trait contributing to plant flooding tolerance.

AB - Waterlogged soils contain monocarboxylic acids produced by anaerobic microorganisms. These “organic acids” can accumulate to phytotoxic levels and promote development of a barrier to radial O2 loss (ROL) in roots of some wetland species. Environmental cues triggering root ROL barrier induction, a feature that together with tissue gas-filled porosity facilitates internal aeration, are important to elucidate for knowledge of plant stress physiology. We tested the hypothesis that comparatively low, non-toxic, concentrations of acetic, propionic, butyric, and/or hexanoic acids might induce root ROL barrier formation in rice. Each organic acid, individually, triggered the ROL barrier in roots but with no effect (acetic or butyric acids) or with only slight effects (propionic or hexanoic acids) on root extension. Transcripts of four genes related to suberin biosynthesis were increased by some of the organic acid treatments. Respiration in root tissues was not, or moderately, inhibited. Beyond a narrow concentration range, however, respiration declined exponentially and the order (least to greatest) for EC50 (effective concentration for 50% inhibition) was butyric, propionic, acetic, then hexanoic acid. An understanding of the environmental cue for root ROL barrier induction should enhance future work to elucidate the molecular regulation of this root trait contributing to plant flooding tolerance.

U2 - 10.1111/pce.13562

DO - 10.1111/pce.13562

M3 - Journal article

C2 - 30989660

SN - 0140-7791

VL - 42

SP - 2183

EP - 2197

JO - Plant, Cell and Environment

JF - Plant, Cell and Environment

IS - 7

ER -