TY - JOUR
T1 - Post-anthesis alternate wetting and moderate soil drying enhances activities of key enzymes in sucrose-to-starch conversion in inferior spikelets of rice
AU - Zhang, Hao
AU - Li, Hongwei
AU - Yuan, Liming
AU - Wang, Zhiqin
AU - Yang, Jianchang
AU - ZHANG, Jianhua
N1 - Funding Information:
This work was supported by the National Natural Science Foundation of China (NSFC-IRRI Joint Research Project 31061140457; General Project 31071360), the National Basic Research Program (973 Program, 2009CB118603), the Natural Science Foundation of Jiangsu Province (BK2009-005), the Hong Kong University Grants Committee (AOE/B-07/99), and the Hong Kong Research Grants Council (HKBU 262809).
PY - 2012/1
Y1 - 2012/1
N2 - This study tested the hypothesis that a post-anthesis moderate soil drying can improve grain filling through regulating the key enzymes in the sucrose-to-starch pathway in the grains of rice (Oryza sativa L.). Two rice cultivars were field grown and two irrigation regimes, alternate wetting and moderate soil drying (WMD) and conventional irrigation (CI, continuously flooded), were imposed during the grain-filling period. The grain-filling rate and activities of four key enzymes in sucrose-to-starch conversion, sucrose synthase (SuSase), adenosine diphosphate-glucose pyrophosphorylase (AGPase), starch synthase (StSase), and starch branching enzyme (SBE), showed no significant difference between WMD and CI regimes for the earlier flowering superior spikelets. However, they were significantly enhanced by the WMD for the later flowering inferior spikelets. The activities of both soluble and insoluble acid invertase in the grains were little affected by the WMD. The two cultivars showed the same tendencies. The activities of SuSase, AGPase, StSase, and SBE in grains were very significantly correlated with the grain-filling rate. The abscisic acid (ABA) concentration in inferior spikelets was remarkably increased in the WMD and very significantly correlated with activities of SuSase, AGPase, StSase, and SBE. Application of ABA on plants under CI produced similar results to those seen in plants receiving WMD. Applying fluridone, an indirect inhibitor of ABA synthesis, produced the opposite effect. The results suggest that post-anthesis WMD could enhance sink strength by regulating the key enzymes involved, and consequently, increase the grain-filling rate and grain weight of inferior spikelets. ABA plays an important role in this process.
AB - This study tested the hypothesis that a post-anthesis moderate soil drying can improve grain filling through regulating the key enzymes in the sucrose-to-starch pathway in the grains of rice (Oryza sativa L.). Two rice cultivars were field grown and two irrigation regimes, alternate wetting and moderate soil drying (WMD) and conventional irrigation (CI, continuously flooded), were imposed during the grain-filling period. The grain-filling rate and activities of four key enzymes in sucrose-to-starch conversion, sucrose synthase (SuSase), adenosine diphosphate-glucose pyrophosphorylase (AGPase), starch synthase (StSase), and starch branching enzyme (SBE), showed no significant difference between WMD and CI regimes for the earlier flowering superior spikelets. However, they were significantly enhanced by the WMD for the later flowering inferior spikelets. The activities of both soluble and insoluble acid invertase in the grains were little affected by the WMD. The two cultivars showed the same tendencies. The activities of SuSase, AGPase, StSase, and SBE in grains were very significantly correlated with the grain-filling rate. The abscisic acid (ABA) concentration in inferior spikelets was remarkably increased in the WMD and very significantly correlated with activities of SuSase, AGPase, StSase, and SBE. Application of ABA on plants under CI produced similar results to those seen in plants receiving WMD. Applying fluridone, an indirect inhibitor of ABA synthesis, produced the opposite effect. The results suggest that post-anthesis WMD could enhance sink strength by regulating the key enzymes involved, and consequently, increase the grain-filling rate and grain weight of inferior spikelets. ABA plays an important role in this process.
KW - Abscisic acid (ABA)
KW - adenosine diphosphate-glucose pyrophosphorylase
KW - alternate wetting and moderate soil drying
KW - grain filling
KW - inferior spikelets
KW - rice (Oryza sativa)
KW - sink strength
KW - superior spikelets
UR - http://www.scopus.com/inward/record.url?scp=84555194875&partnerID=8YFLogxK
U2 - 10.1093/jxb/err263
DO - 10.1093/jxb/err263
M3 - Journal article
C2 - 21926094
AN - SCOPUS:84555194875
SN - 0022-0957
VL - 63
SP - 215
EP - 227
JO - Journal of Experimental Botany
JF - Journal of Experimental Botany
IS - 1
ER -