Variation in vein density and mesophyll cell architecture in a rice deletion mutant population

• Published in: Journal of experimental botany Vol. 63; no. 12; pp. 4563 - 4570
• Main Authors: Smillie, I.R.A, Pyke, K.A, Murchie, E.H
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press [etc.] 01.07.2012; OXFORD UNIVERSITY PRESS; Oxford University Press; OUP
• Subjects: Anatomy; Biological and medical sciences; Body Patterning; Bundle sheath cells; C4 plants; cell division; Cell lines; Fundamental and applied biological sciences. Psychology; grain yield; Leaves; mesophyll; Mesophyll cells; Mesophyll Cells - ultrastructure; mutants; Oryza - anatomy & histology; Oryza - genetics; Oryza - growth & development; photosynthesis; Plant cells; Plant Leaves - anatomy & histology; Plant Leaves - genetics; Plant Leaves - growth & development; Plant physiology and development; Plant Vascular Bundle - anatomy & histology; Plant Vascular Bundle - genetics; Plant Vascular Bundle - growth & development; Plant veins; Plants; reproduction; RESEARCH PAPER; Rice; Sage; Sequence Deletion; Leaf morphology; Monocotyledones; Architecture; mesophyll cell; Oryza sativa L; Spacing; Plant leaf; rice; Density; vein spacing; Cereal crop; Oryza sativa; Mesophyll; Gramineae; Morphology; Angiospermae; Botany; Deletion; Spermatophyta; Mutation
• ISSN: 0022-0957; 1460-2431
• DOI: 10.1093/jxb/ers142

There is a need to develop rice plants with improved photosynthetic capacity and efficiency in order to enhance potential grain yield. Alterations in internal leaf morphology may be needed to underpin some of these improvements. One target is the production of a ‘Kranz-like’ anatomy, commonly considered to be required to achieve the desired levels of photosynthesis seen in C4 crops. Kranz anatomy typically has two or three mesophyll cells interspersing adjacent veins. As a first step to determining the potential for such anatomical modifications in rice leaves, a population of rice deletion mutants was analysed for alterations in vein patterning and mesophyll cells in the interveinal regions. Significant variation is demonstrated in vein arrangement and the sequential distribution of major and minor veins across the leaf width, although there is a significant correlation between the total number of veins present and the width of the leaf. Thus the potential is demonstrated for modifying rice leaf structure. Six distinct rice mutant lines, termed altered leaf morphology (alm) mutants, were analysed for the architecture of their interveinal mesophyll cell arrangement. It is shown that in these mutant lines, the distance between adjacent minor veins and adjacent minor and major veins is essentially determined by the size of the interveinal mesophyll cells rather than changes in mesophyll cell number across this region, and hence interveinal distance changes as a result of cell expansion rather than cell division. This observation will be important when developing screens for traits relevant for the introduction of Kranz anatomy into rice.This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.0/uk/) which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original work is properly cited.This paper is available online free of all access charges (see http://jxb.oxfordjournals.org/open_access.html for further details)