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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Bioproducts Research » Research » Publications at this Location » Publication #316200

Research Project: Bioproducts from Agricultural Feedstocks

Location: Bioproducts Research

Title: Rice microstructure

Author
item Wood, Delilah - De
item Williams, Tina
item Orts, William - Bill

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/8/2015
Publication Date: 10/1/2015
Citation: Wood, D.F., Williams, T.G., Orts, W.J. 2015. Rice microstructure. Meeting Abstract. p.359.

Interpretive Summary:

Technical Abstract: An understanding of plant structure is desirable to obtain a clear idea of the overall impact of a crop. A mature rice plant consists of leafy components (left in the field post-harvest) and paddy rice (collected). The rice plant is supported by a hollow stem (culm) with leaf sheaths attached to nodes. Rice panicles are located on the uppermost node of a culm. Each panicle has numerous branches and supports the growth of a single spikelet at each terminus. Each spikelet (paddy rice) consists of a caryopsis (brown rice grain) and the surrounding hull. The hull consists of a palea and lemma which are subtended by glumes and a rachilla. The lemma and palea have outer epidermis, highly lignified sclerenchyma, spongy parenchyma and inner epidermis. The caryopsis consists of a seed and tightly adherent pericarp (fruit coat). The pericarp is comprised of a thin cuticle covering the epidermis, several layers of partly crushed, "spongy" parenchyma and cross and tube cells. The seed includes the testa, nucellus, embryo and endosperm. The testa and nucellus consist of a single crushed layer of cells, the testa and nucellar cuticles and the remains of the nucellar cells. The embryo consists of the scutellum, embryonic axis and various sheathing structures containing storage proteins, lipids and meristematic tissues. The endosperm consists of an outer aleurone layer and inner starchy endosperm. The aleurone layer contains spherical storage proteins. Many of the storage proteins in the aleurone cells contain inclusions of phytic acid. The starchy endosperm contains thin-walled parenchyma cells filled with compound starch granules. The youngest starchy endosperm cells are located at the periphery of the starchy endosperm and also contain protein and lipid bodies. The protein and lipid bodies diminish in number toward the interior of the starchy endosperm.