Related Experiment Video
Updated: Jul 2, 2025
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A Strategy to Validate the Role of Callose-mediated Plasmodesmal Gating in the Tropic Response
Published on: April 17, 2016
10.3K
APP1/NTL9-CalS8 module ensures proper phloem differentiation by stabilizing callose accumulation and symplastic
Jie Liu1, Yongxiao Fan1, Yao Liu1
1State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Academy for Advanced Interdisciplinary Studies, Henan University, Kaifeng, 475004, China.
The New Phytologist
|February 20, 2024
Summary
A study on Arabidopsis root development reveals that the APP1 protein regulates phloem sieve element (SE) differentiation. The APP1-CalS8 module is crucial for SE maturation and phloem transport, ensuring proper root growth.
Area of Science:
- Plant Biology
- Developmental Biology
- Molecular Genetics
Background:
- Phloem sieve elements (PSE) are vital for nutrient transport in plants.
- The differentiation process of PSE and its regulatory mechanisms are not fully understood.
- Phloem pole pericycle (PPP) cells play a key role in supporting PSE development.
Purpose of the Study:
- To investigate the molecular mechanisms underlying phloem sieve element differentiation in Arabidopsis roots.
- To identify key regulators involved in maintaining the progression of PSE developmental stages.
- To elucidate the function of the APP1 gene in PSE development and phloem transport.
Main Methods:
- Identification and characterization of a gain-of-function mutant (app1D) in Arabidopsis.
- Analysis of gene expression patterns, specifically for CALLOSE SYNTHASE 8 (CalS8).
- Experimental manipulation of symplastic transport to study the role of APP1 localization and function.
Main Results:
- The app1D mutant exhibits ectopic expression of CalS8, leading to callose accumulation and impaired SE differentiation.
- This mutation impedes phloem transport and inhibits overall root growth.
- Wild-type APP1 translocates to the nucleus in specific PPP cells, a process sensitive to symplastic transport disruption.
Conclusions:
- The APP1-CalS8 module is identified as a critical regulator of SE differentiation in Arabidopsis roots.
- APP1 activity and its nuclear import are essential for modulating symplastic communication during PSE development.
- Proper functioning of this module is crucial for successful phloem transport and root growth.
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