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
PY - 2019/7/1
Y1 - 2019/7/1
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.
KW - aerenchyma
KW - lignin
KW - Oryza sativa
KW - ROL
KW - root internal aeration
KW - root respiration
KW - soil phytotoxins
KW - soil waterlogging
KW - suberin
KW - transcripts
UR - http://www.scopus.com/inward/record.url?scp=85067289620&partnerID=8YFLogxK
U2 - 10.1111/pce.13562
DO - 10.1111/pce.13562
M3 - Article
C2 - 30989660
AN - SCOPUS:85067289620
VL - 42
SP - 2183
EP - 2197
JO - Plant, Cell and Environment.
JF - Plant, Cell and Environment.
SN - 0140-7791
IS - 7
ER -