PMID- 29047257
OWN - NLM
STAT- MEDLINE
DCOM- 20180709
LR  - 20240204
IS  - 0219-1032 (Electronic)
IS  - 1016-8478 (Print)
IS  - 1016-8478 (Linking)
VI  - 40
IP  - 10
DP  - 2017 Oct
TI  - Rice 7-Hydroxymethyl Chlorophyll a Reductase Is Involved in the Promotion of 
      Chlorophyll Degradation and Modulates Cell Death Signaling.
PG  - 773-786
LID - 10.14348/molcells.2017.0127 [doi]
AB  - The loss of green coloration via chlorophyll (Chl) degradation typically occurs 
      during leaf senescence. To date, many Chl catabolic enzymes have been identified 
      and shown to interact with light harvesting complex II to form a Chl degradation 
      complex in senescing chloroplasts; this complex might metabolically channel 
      phototoxic Chl catabolic intermediates to prevent oxidative damage to cells. The 
      Chl catabolic enzyme 7-hydroxymethyl Chl a reductase (HCAR) converts 
      7-hydroxymethyl Chl a (7-HMC a) to Chl a. The rice (Oryza sativa) genome contains 
      a single HCAR homolog (OsHCAR), but its exact role remains unknown. Here, we show 
      that an oshcar knockout mutant exhibits persistent green leaves during both 
      dark-induced and natural senescence, and accumulates 7-HMC a and pheophorbide a 
      (Pheo a) in green leaf blades. Interestingly, both rice and Arabidopsis hcar 
      mutants exhibit severe cell death at the vegetative stage; this cell death 
      largely occurs in a light intensity-dependent manner. In addition, 7-HMC a 
      treatment led to the generation of singlet oxygen ((1)O(2)) in Arabidopsis and 
      rice protoplasts in the light. Under herbicide-induced oxidative stress 
      conditions, leaf necrosis was more severe in hcar plants than in wild type, and 
      HCAR-overexpressing plants were more tolerant to reactive oxygen species than 
      wild type. Therefore, in addition to functioning in the conversion of 7-HMC a to 
      Chl a in senescent leaves, HCAR may play a critical role in protecting plants 
      from high light-induced damage by preventing the accumulation of 7-HMC a and Pheo 
      a in developing and mature leaves at the vegetative stage.
FAU - Piao, Weilan
AU  - Piao W
AD  - Department of Plant Science, Plant Genomics and Breeding Institute, and Research 
      Institute of Agriculture and Life Sciences, Seoul National University, Seoul 
      08826, Korea.
FAU - Han, Su-Hyun
AU  - Han SH
AD  - Department of Plant Science, Plant Genomics and Breeding Institute, and Research 
      Institute of Agriculture and Life Sciences, Seoul National University, Seoul 
      08826, Korea.
FAU - Sakuraba, Yasuhito
AU  - Sakuraba Y
AD  - Department of Plant Science, Plant Genomics and Breeding Institute, and Research 
      Institute of Agriculture and Life Sciences, Seoul National University, Seoul 
      08826, Korea.
FAU - Paek, Nam-Chon
AU  - Paek NC
AD  - Department of Plant Science, Plant Genomics and Breeding Institute, and Research 
      Institute of Agriculture and Life Sciences, Seoul National University, Seoul 
      08826, Korea.
LA  - eng
PT  - Journal Article
DEP - 20171017
PL  - United States
TA  - Mol Cells
JT  - Molecules and cells
JID - 9610936
RN  - 0 (Arabidopsis Proteins)
RN  - 1406-65-1 (Chlorophyll)
RN  - 17778-80-2 (Singlet Oxygen)
RN  - EC 1.- (7-hydroxymethyl chlorophyll a reductase, Arabidopsis)
RN  - EC 1.- (Oxidoreductases)
RN  - YF5Q9EJC8Y (Chlorophyll A)
SB  - IM
MH  - Arabidopsis/*genetics/growth & development
MH  - Arabidopsis Proteins/*genetics
MH  - Cell Death/genetics
MH  - Chlorophyll/*genetics/metabolism
MH  - Chlorophyll A
MH  - Chloroplasts/genetics/metabolism
MH  - Gene Expression Regulation, Plant
MH  - Mutation
MH  - Oryza/*genetics/growth & development
MH  - Oxidoreductases/*genetics
MH  - Signal Transduction
MH  - Singlet Oxygen/metabolism
PMC - PMC5682254
OTO - NOTNLM
OT  - 7-hydroxymethyl chlorophyll a reductase (HCAR)
OT  - cell death
OT  - chlorophyll
OT  - chlorophyll catabolic enzyme
OT  - rice
EDAT- 2017/10/20 06:00
MHDA- 2018/07/10 06:00
PMCR- 2017/10/31
CRDT- 2017/10/20 06:00
PHST- 2017/07/08 00:00 [received]
PHST- 2017/08/10 00:00 [revised]
PHST- 2017/08/23 00:00 [accepted]
PHST- 2017/10/20 06:00 [pubmed]
PHST- 2018/07/10 06:00 [medline]
PHST- 2017/10/20 06:00 [entrez]
PHST- 2017/10/31 00:00 [pmc-release]
AID - S1016-8478(23)00667-2 [pii]
AID - molce-40-10-773 [pii]
AID - 10.14348/molcells.2017.0127 [doi]
PST - ppublish
SO  - Mol Cells. 2017 Oct;40(10):773-786. doi: 10.14348/molcells.2017.0127. Epub 2017 
      Oct 17.