SMALL GRAIN 1, which encodes a mitogen‐activated protein kinase kinase 4, influences grain size in rice

Citations Over TimeTop 10% of 2013 papers

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 (OsMKK4). Relatively higher expression of OsMKK4/SMG1 was detected in younger organs than in older ones, consistent with its role in cell proliferation. Green fluorescent protein (GFP)-OsMKK4/SMG1 fusion proteins appear to be distributed ubiquitously in plant cells. Further results revealed that OsMKK4 influenced brassinosteroid (BR) responses and the expression of BR-related genes. Thus, our findings have identified OsMKK4 as a factor for grain size, and suggest a possible link between the MAPK pathways and BRs in grain growth.

Related Papers

• A Preliminary Analysis of Characters of Rice Panicles(2003)
• Effect of exogenous GA_(3) on panicle character of different rice type(2005)
• → PANICLE APICAL ABORTION 3 Controls Panicle Development and Seed Size in Rice(2021)1 cited
• Study on characteristics of panicle and grain structure matched with high-yield for new hybrid rice combination "Teyou 649"(2006)
• Effect of Panicle Distribution Mode on Different Panicle Type Rice Population(2003)