PMID- 17297616
OWN - NLM
STAT- MEDLINE
DCOM- 20070830
LR  - 20220331
IS  - 0721-7714 (Print)
IS  - 0721-7714 (Linking)
VI  - 26
IP  - 7
DP  - 2007 Jul
TI  - Knockout of a starch synthase gene OsSSIIIa/Flo5 causes white-core floury 
      endosperm in rice (Oryza sativa L.).
PG  - 1083-95
AB  - To elucidate the role of SSIIIa during starch synthesis in rice (Oryza sativa L.) 
      endosperm, we characterized null mutants of this gene, generated by T-DNA 
      insertions. Scanning electron microscope (SEM) analysis revealed that the starch 
      granules in these mutants are smaller and rounder compared with the wild type 
      controls, and that the mutant endosperm is characterized by a loosely packed 
      central portion exhibiting a floury-like phenotype. Hence, the OsSSIIIa (Oryza 
      sativa SSIIIa) mutations are referred to as white-core floury endosperm 5-1 
      (flo5-1) and flo5-2. Based upon their X-ray diffraction patterns, the 
      crystallinity of the starch in the flo5 mutant endosperm is decreased compared 
      with wild type. Through determination of the chain-length distribution of the 
      mutant endosperm starch, we found that flo5-1 and flo5-2 mutants have reduced the 
      content of long chains with degree of polymerization (DP) 30 or greater compared 
      with the controls. This suggests that OsSSIIIa/Flo5 plays an important role in 
      generating relatively long chains in rice endosperm. In addition, DP 6 to 8 and 
      DP 16 to 20 appeared to be reduced in endosperm starch of flo5-1 and flo5-2, 
      whereas DP 9 to 15 and DP 22 to 29 were increased in these mutants. By the use of 
      differential scanning calorimetry (DSC), the gelatinization temperatures of 
      endosperm starch were found to be 1-5 degrees C lower than those of the control. 
      We propose a distinct role for OsSSIIIa/Flo5 and the coordinated action of other 
      SS isoforms during starch synthesis in the seed endosperm of rice.
FAU - Ryoo, Nayeon
AU  - Ryoo N
AD  - Plant Metabolism Research Center and Graduate School of Biotechnology, Kyung Hee 
      University, Yongin 446-701, Korea. ryoo1009@khu.ac.kr
FAU - Yu, Chul
AU  - Yu C
FAU - Park, Cheon-Seok
AU  - Park CS
FAU - Baik, Moo-Yeol
AU  - Baik MY
FAU - Park, In Myoung
AU  - Park IM
FAU - Cho, Man-Ho
AU  - Cho MH
FAU - Bhoo, Seong Hee
AU  - Bhoo SH
FAU - An, Gynheung
AU  - An G
FAU - Hahn, Tae-Ryong
AU  - Hahn TR
FAU - Jeon, Jong-Seong
AU  - Jeon JS
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20070213
PL  - Germany
TA  - Plant Cell Rep
JT  - Plant cell reports
JID - 9880970
RN  - 0 (Protein Isoforms)
RN  - 9037-22-3 (Amylopectin)
RN  - EC 2.4.1.21 (Starch Synthase)
SB  - IM
MH  - Amylopectin/biosynthesis/genetics
MH  - *Gene Deletion
MH  - Gene Expression Regulation, Plant
MH  - Oryza/enzymology/*genetics/*metabolism
MH  - Protein Isoforms
MH  - Seeds/enzymology/genetics/*metabolism
MH  - Starch Synthase/*deficiency/genetics
EDAT- 2007/02/14 09:00
MHDA- 2007/08/31 09:00
CRDT- 2007/02/14 09:00
PHST- 2006/12/03 00:00 [received]
PHST- 2007/01/15 00:00 [accepted]
PHST- 2007/01/12 00:00 [revised]
PHST- 2007/02/14 09:00 [pubmed]
PHST- 2007/08/31 09:00 [medline]
PHST- 2007/02/14 09:00 [entrez]
AID - 10.1007/s00299-007-0309-8 [doi]
PST - ppublish
SO  - Plant Cell Rep. 2007 Jul;26(7):1083-95. doi: 10.1007/s00299-007-0309-8. Epub 2007 
      Feb 13.