TY - JOUR
T1 - Hormones in the grains and roots in relation to post-anthesis development of inferior and superior spikelets in japonica/indica hybrid rice
AU - Zhang, Hao
AU - Tan, Guilu
AU - Yang, Linian
AU - Yang, Jianchang
AU - ZHANG, Jianhua
AU - Zhao, Buhong
N1 - Funding Information:
The authors gratefully acknowledge the grants from the National Basic Research Program (973 Program, 2009CB118603), the National Natural Science Foundation of China (30671225, 30771274, 30854755), the Natural Science Foundation of Jiangsu Province (BK2006069, BK2007071), Hong Kong University Grants Committee (AOE/B-07/99), and Hong Kong Baptist University Matching Research Fund.
PY - 2009/3
Y1 - 2009/3
N2 - Grain filling is usually not adequate in later-flowering inferior spikelets in japonica/indica (J/I) hybrid rice (Oryza sativa) although it shows stronger hybrid vigor than indica/indica (I/I) hybrid. This study investigated the potential causes by examining changes in zeatin (Z) + zeatin riboside (ZR), indole-3-acetic acid (IAA), gibberellins (GAs, GA1 + GA4), and abscisic acid (ABA) in spikelets and roots during the grain filling period. The inferior spikelets of J/I hybrid exhibited low rate of endosperm cell division and slow grain filling. During the early grain filing period, they had less Z + ZR, IAA, and ABA, but more GAs, than the earlier-flowering superior spikelets. If compared to the inferior spikelets of the I/I hybrid, the J/I inferior spikelets also had less Z + ZR, IAA, and ABA. Rates of endosperm cell division and grain filling were positively and significantly correlated with Z + ZR and ABA contents in both grains and roots or IAA in grains, whereas not significantly correlated with GAs either in grains or roots or IAA in roots. Applications of kinetin, IAA, or ABA to spikelets, or kinetin and ABA to roots, enhanced cell division and grain filling in the inferior spikelets. Results suggest that low contents of cytokinins and ABA in both grains and roots and low contents of IAA in grains may result in the poor filling of inferior spikelets in the J/I hybrid.
AB - Grain filling is usually not adequate in later-flowering inferior spikelets in japonica/indica (J/I) hybrid rice (Oryza sativa) although it shows stronger hybrid vigor than indica/indica (I/I) hybrid. This study investigated the potential causes by examining changes in zeatin (Z) + zeatin riboside (ZR), indole-3-acetic acid (IAA), gibberellins (GAs, GA1 + GA4), and abscisic acid (ABA) in spikelets and roots during the grain filling period. The inferior spikelets of J/I hybrid exhibited low rate of endosperm cell division and slow grain filling. During the early grain filing period, they had less Z + ZR, IAA, and ABA, but more GAs, than the earlier-flowering superior spikelets. If compared to the inferior spikelets of the I/I hybrid, the J/I inferior spikelets also had less Z + ZR, IAA, and ABA. Rates of endosperm cell division and grain filling were positively and significantly correlated with Z + ZR and ABA contents in both grains and roots or IAA in grains, whereas not significantly correlated with GAs either in grains or roots or IAA in roots. Applications of kinetin, IAA, or ABA to spikelets, or kinetin and ABA to roots, enhanced cell division and grain filling in the inferior spikelets. Results suggest that low contents of cytokinins and ABA in both grains and roots and low contents of IAA in grains may result in the poor filling of inferior spikelets in the J/I hybrid.
KW - Abscisic acid
KW - Endosperm cell
KW - Gibberellins
KW - Grain filling
KW - Indole-3-acetic acid
KW - Japonica/indica hybrid rice (Oryza sativa)
KW - Zeatin + zeatin riboside
UR - http://www.scopus.com/inward/record.url?scp=59049091432&partnerID=8YFLogxK
U2 - 10.1016/j.plaphy.2008.11.012
DO - 10.1016/j.plaphy.2008.11.012
M3 - Journal article
C2 - 19117763
AN - SCOPUS:59049091432
SN - 0981-9428
VL - 47
SP - 195
EP - 204
JO - Plant Physiology and Biochemistry
JF - Plant Physiology and Biochemistry
IS - 3
ER -