Nitrogen Deficiency-Induced Decrease in Cytokinins Content Promotes Rice Seminal Root Growth by Promoting Root Meristem Cell Proliferation and Cell Elongation
Open Access
- 9 April 2020
- Vol. 9 (4), 916
- https://doi.org/10.3390/cells9040916
Abstract
Rice (Oryza sativa L.) seedlings grown under nitrogen (N) deficiency conditions show a foraging response characterized by increased root length. However, the mechanism underlying this developmental plasticity is still poorly understood. In this study, the mechanism by which N deficiency influences rice seminal root growth was investigated. The results demonstrated that compared with the control (1 mM N) treatment, N deficiency treatments strongly promoted seminal root growth. However, the N deficiency-induced growth was negated by the application of zeatin, which is a type of cytokinin (CK). Moreover, the promotion of rice seminal root growth was correlated with a decrease in CK content, which was due to the N deficiency-mediated inhibition of CK biosynthesis through the down-regulation of CK biosynthesis genes and an enhancement of CK degradation through the up-regulation of CK degradation genes. In addition, the N deficiency-induced decrease in CK content not only enhanced the root meristem cell proliferation rate by increasing the meristem cell number via the down-regulation of OsIAA3 and up-regulation of root-expressed OsPLTs, but also promoted root cell elongation by up-regulating cell elongation-related genes, including root-specific OsXTHs and OsEXPs. Taken together, our data suggest that an N deficiency-induced decrease in CK content promotes the seminal root growth of rice seedlings by promoting root meristem cell proliferation and cell elongation.Funding Information
- the national key Research and Development Program of China (No. 2016YFD0300102)
- the Fundamental Research Funds for the Central Universities (No. 2662018PY076)
This publication has 57 references indexed in Scilit:
- Nitrogen signalling pathways shaping root system architecture: an updateCurrent Opinion in Plant Biology, 2014
- Strigolactones are involved in phosphate- and nitrate-deficiency-induced root development and auxin transport in riceJournal of Experimental Botany, 2014
- Maize root growth angles become steeper under low N conditionsField Crops Research, 2013
- Fertilizing Nature: A Tragedy of Excess in the CommonsPLoS Biology, 2011
- Improving nitrogen fertilization in rice by sitespecific N management. A reviewAgronomy for Sustainable Development, 2010
- Reducing environmental risk by improving N management in intensive Chinese agricultural systemsProceedings of the National Academy of Sciences of the United States of America, 2009
- Yield Physiology of RiceJournal of Plant Nutrition, 2007
- Rice root growth and nutrient uptake as influenced by organic manure in continuously and alternately flooded paddy soilsAgricultural Water Management, 2004
- Nitrate-specific and cytokinin-mediated nitrogen signaling pathways in plantsJournal of Plant Research, 2003
- Nutrient Supply and the Growth of the Seminal Root System in BarleyJournal of Experimental Botany, 1973