title: Grain Filling Characteristics and Their Relations with Endogenous Hormones in Large- and Small-Grain Mutants of Rice.
abstract: This study determined if the variation in grain filling parameters between two different spikelet types of rice (Oryza sativa L.) is regulated by the hormonal levels in the grains. Two rice mutants, namely, a large-grain mutant (AZU-M) and a small-grain mutant (ZF802-M), and their respective wild types (AZU-WT and ZF802-WT) were grown in the field. The endosperm cell division rate, filling rate, and hormonal levels: zeatin + zeatin riboside (Z+ZR), indo-3-acetic acid (IAA), polyamines (PAs), and abscisic acid (ABA) were determined. The results showed that there was no significant difference between the filling and endosperm cell division rates. These rates were synchronous between the superior and inferior spikelets for both mutants. However, the abovementioned parameters were significantly different between the two spikelet types for the two wild types. The superior spikelets filled faster and their filling rate was higher compared to the inferior ones. Changes in the concentrations of plant hormones were consistent with the observed endosperm cell division rate and the filling rate for both types of spikelets of mutant and wild type plants. Regression analysis showed a significant positive correlation between cell division and filling rates with the concentrations of the investigated hormones. Exogenous chemical application verified the role of ABA, IAA, and PAs in grain filling. The results indicate that poor filling of inferior spikelets in rice occurs primarily due to the reduced hormone concentrations therein, leading to lower division rate of endosperm cells, fewer endosperm cells, slower filling rate, and smaller grain weight.
authors: Jiangsu Key Laboratory of Crop Genetics and Physiology, Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, China.
authors: Weiyang
authors: W
authors: Zhang
authors: Jiangsu Key Laboratory of Crop Genetics and Physiology, Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, China.
authors: Zhuanqin
authors: Z
authors: Cao
authors: Jiangsu Key Laboratory of Crop Genetics and Physiology, Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, China.
authors: Qun
authors: Q
authors: Zhou
authors: Jiangsu Key Laboratory of Crop Genetics and Physiology, Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, China.
authors: Jing
authors: J
authors: Chen
authors: Jiangsu Key Laboratory of Crop Genetics and Physiology, Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, China.
authors: Gengwen
authors: G
authors: Xu
authors: Jiangsu Key Laboratory of Crop Genetics and Physiology, Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, China.
authors: Junfei
authors: J
authors: Gu
authors: Jiangsu Key Laboratory of Crop Genetics and Physiology, Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, China.
authors: Lijun
authors: L
authors: Liu
authors: Jiangsu Key Laboratory of Crop Genetics and Physiology, Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, China.
authors: Zhiqin
authors: Z
authors: Wang
authors: Jiangsu Key Laboratory of Crop Genetics and Physiology, Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, China.
authors: Jianchang
authors: J
authors: Yang
authors: Jiangsu Key Laboratory of Crop Genetics and Physiology, Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, China.
authors: Hao
authors: H
authors: Zhang
mesh_terms: D000040:Abscisic Acid / Q000032:analysis / Q000302:isolation & purification; D002523:Edible Grain / Q000254:growth & development / Q000378:metabolism; D056625:Endosperm / Q000187:drug effects / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D008935:Mitoguazone / Q000494:pharmacology; D012275:Oryza / Q000254:growth & development / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000032:analysis* / Q000302:isolation & purification; D030821:Plants, Genetically Modified / Q000254:growth & development / Q000378:metabolism; D011073:Polyamines / Q000032:analysis / Q000302:isolation & purification; D011700:Putrescine / Q000494:pharmacology; D013095:Spermidine / Q000494:pharmacology; D015026:Zeatin / Q000032:analysis / Q000302:isolation & purification
chemical_list: D010937:Plant Growth Regulators; D011073:Polyamines; D000040:Abscisic Acid; D015026:Zeatin; D008935:Mitoguazone; D013095:Spermidine; D011700:Putrescine