Proteomic analysis of positive influence of alternate wetting and moderate soil drying on the process of rice grain filling

Abstract Background Rice is an important food source for humans worldwide. Because of its nutritional and agricultural significance, a number of studies addressed various aspects of rice grain development and grain filling. Nevertheless, the molecular processes underlying grain filling and development, and in particular the contributions of different grain tissues to these processes, are not understood. Main Text Using RNA-sequencing, we profiled gene expression activity in grain tissues comprised of cross cells (CC), the nucellar epidermis (NE), ovular vascular trace (OVT), endosperm (EN) and the aleurone layer (AL). These tissues were dissected using laser capture microdissection (LCM) at three distinct grain development stages. The mRNA expression datasets offer comprehensive and new insights into the gene expression patterns in different rice grain tissues and their contributions to grain development. Comparative analysis of the different tissues revealed their similar and/or unique functions, as well as the spatio-temporal regulation of common and tissue-specific genes. The expression patterns of genes encoding hormones and transporters indicate an important role of the OVT tissue in metabolite transport during grain development. Gene co-expression network prediction on OVT-specific genes identified several distinct and common development-specific transcription factors. Further analysis of enriched DNA sequence motifs proximal to OVT-specific genes revealed known and novel DNA sequence motifs relevant to rice grain development. Conclusion Together, the dataset of gene expression in rice grain tissues is a novel and useful resource for further work to dissect the molecular and metabolic processes during rice grain development.

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Effect of Temperature during Grain Filling Stage on Endosperm Structure and Apperance Quality of Aromatic Rice

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.460.286 ◽

2012 ◽

Vol 460 ◽

pp. 286-289 ◽

Cited By ~ 1

Author(s):

Zhen Jiang Xu ◽

Li Zhong Xiao ◽

Hong Liu ◽

Yong Hao Ren ◽

Zhi Lin Li

Keyword(s):

Grain Filling ◽

Effect Of Temperature ◽

Rice Grain ◽

Aromatic Rice ◽

Starch Granules ◽

Filling Stage ◽

Appearance Quality ◽

Endosperm Structure ◽

Grain Filling Stage

Based on the experiment of two inbred aromatic rice varieties and one hybrid aromatic rice line treated under four different temperatures( daymean temperature 21°C, 23°C, 26°C and 30°C respectively) during grain filling stage in phytotrons, the shape and arrangement of endosperm starch granules in rice grain transection were observed by scanning electron microscope and the related characteristics of rice grain qualities of chalky percent and chalkiness were analyzed at the same time. The results showed that under the lower temperature( daymean temperature21°C and 23°C), many large compound starch granules with clear angulars packed together regularly without significant natural gaps bewteen starch granules in the tansectional endosperm. However, with the increase of temperature, starch granules in the transectional endosperm were changed from regularly shaped and closely and orderly arranged to various shaped and chaoticly arranged with obvious natural gaps between starch granules, which was closely consistent with the poorer appearance quality under the higher temperature, which indicated that the endosperm structure is closely related with appearance quality of aromatic rice.

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The Rho-family GTPase OsRac1 controls rice grain size and yield by regulating cell division

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1902321116 ◽

2019 ◽

Vol 116 (32) ◽

pp. 16121-16126 ◽

Cited By ~ 5

Author(s):

Ying Zhang ◽

Yan Xiong ◽

Renyi Liu ◽

Hong-Wei Xue ◽

Zhenbiao Yang

Keyword(s):

Grain Size ◽

Cell Division ◽

Grain Yield ◽

Molecular Mechanisms ◽

Grain Filling ◽

High Yield ◽

Rice Grain ◽

Rop Gtpase ◽

Key Factor ◽

Grain Width

Grain size is a key factor for determining grain yield in crops and is a target trait for both domestication and breeding, yet the mechanisms underlying the regulation of grain size are largely unclear. Here we show that the grain size and yield of rice (Oryza sativa) is positively regulated by ROP GTPase (Rho-like GTPase from plants), a versatile molecular switch modulating plant growth, development, and responses to the environment. Overexpression of rice OsRac1ROP not only increases cell numbers, resulting in a larger spikelet hull, but also accelerates grain filling rate, causing greater grain width and weight. As a result, OsRac1 overexpression improves grain yield in O. sativa by nearly 16%. In contrast, down-regulation or deletion of OsRac1 causes the opposite effects. RNA-seq and cell cycle analyses suggest that OsRac1 promotes cell division. Interestingly, OsRac1 interacts with and regulates the phosphorylation level of OsMAPK6, which is known to regulate cell division and grain size in rice. Thus, our findings suggest OsRac1 modulates rice grain size and yield by influencing cell division. This study provides insights into the molecular mechanisms underlying the control of rice grain size and suggests that OsRac1 could serve as a potential target gene for breeding high-yield crops.

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Irrigation management for arsenic mitigation in rice grain: Timing and severity of a single soil drying

The Science of The Total Environment ◽

10.1016/j.scitotenv.2018.08.216 ◽

2019 ◽

Vol 649 ◽

pp. 300-307 ◽

Cited By ~ 12

Author(s):

Daniela R. Carrijo ◽

Chongyang Li ◽

Sanjai J. Parikh ◽

Bruce A. Linquist

Keyword(s):

Irrigation Management ◽

Soil Drying ◽

Rice Grain

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Novel molecular and cell biological insights into function of rice α-amylase

Amylase ◽

10.1515/amylase-2018-0004 ◽

2018 ◽

Vol 2 (1) ◽

pp. 30-38 ◽

Cited By ~ 3

Author(s):

Toshiaki Mitsui ◽

Akihito Ochiai ◽

Hiromoto Yamakawa ◽

Kentaro Kaneko ◽

Aya Kitajima-Koga ◽

...

Keyword(s):

Intracellular Transport ◽

Starch Synthesis ◽

Grain Filling ◽

Binding Pocket ◽

Rice Grain ◽

Active Site Cleft ◽

Key Factor ◽

Organ Specific ◽

Basic Biology ◽

Grain Chalkiness

Abstract α-Amylases have been of interest in diverse fields for many years because of their importance in basic biology, agriculture, and industry. Starch hydrolysis in plants has been studied extensively in germinating cereal seeds. It is generally accepted that α-amylases are secretory enzymes with a pivotal role in the breakdown of starch reserves in the endosperm. Intriguingly, however, recent investigations reveal that some α-amylases degrade starch in the plastids of living cells. The recent solving of the crystal structure of rice AmyI-1 isoform shows that the binding pocket of starch binding site 1 situated outside of the active site cleft interacts with the substances other than oligosaccharides. These findings provided novel insights into structural and cell biological aspects of α-amylase functions in intracellular transport, organelle targeting, and organ-specific actions. Under global warming, abnormal high temperatures during rice grain filling increase grain chalkiness, resulting in yield loss. Intensive “omics” analyses of developing caryopses and mature grains grown under heat stress showed the downregulation of starch synthesis enzymes and the upregulation of α-amylases. Transgenic studies using ectopic overexpression and suppression of α-amylase revealed that α-amylase is a key factor in grain chalkiness. Here we discuss unique new functions of α-amylase in rice cells.

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