In:
The Plant Journal, Wiley, Vol. 77, No. 4 ( 2014-02), p. 547-557
Abstract:
Although grain size is one of the most important components of grain yield, little information is known about the mechanisms that determine final grain size in crops. Here we characterize rice small grain1 ( smg1 ) mutants, which exhibit small and light grains, dense and erect panicles and comparatively slightly shorter plants. The short grain and panicle phenotypes of smg1 mutants are caused by a defect in cell proliferation. The smg1 mutations were identified, using a map‐based cloning approach, in mitogen‐activated protein kinase kinase 4 ( Os MKK 4 ). Relatively higher expression of Os MKK 4/ SMG 1 was detected in younger organs than in older ones, consistent with its role in cell proliferation. Green fluorescent protein ( GFP )–Os MKK 4/ SMG 1 fusion proteins appear to be distributed ubiquitously in plant cells. Further results revealed that Os MKK 4 influenced brassinosteroid ( BR ) responses and the expression of BR ‐related genes. Thus, our findings have identified Os MKK 4 as a factor for grain size, and suggest a possible link between the MAPK pathways and BR s in grain growth.
Type of Medium:
Online Resource
ISSN:
0960-7412
,
1365-313X
DOI:
10.1111/tpj.2014.77.issue-4
Language:
English
Publisher:
Wiley
Publication Date:
2014
detail.hit.zdb_id:
2020961-7
SSG:
12
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