The Arabidopsis gene DIG6 encodes a large 60S subunit nuclear export GTPase 1 that is involved in ribosome biogenesis and affects multiple auxin-regulated development processes.
The circularly permuted GTPase large subunit GTPase 1 (LSG1) is involved in the maturation step of the 60S ribosome and is essential for cell viability in yeast. Here, an Arabidopsis mutant dig6 (drought inhibited growth of lateral roots) was isolated. The mutant exhibited multiple auxin-related phenotypes, which included reduced lateral root number, altered leaf veins, and shorter roots. Genetic mapping combined with next-generation DNA sequencing identified that the mutation occurred in AtLSG1-2. This gene was highly expressed in regions of auxin accumulation. Ribosome profiling revealed that a loss of function of AtLSG1-2 led to decreased levels of monosomes, further demonstrating its role in ribosome biogenesis. Quantitative proteomics showed that the expression of certain proteins involved in ribosome biogenesis was differentially regulated, indicating that ribosome biogenesis processes were impaired in the mutant. Further investigations showed that an AtLSG1-2 deficiency caused the alteration of auxin distribution, response, and transport in plants. It is concluded that AtLSG1-2 is integral to ribosome biogenesis, consequently affecting auxin homeostasis and plant development.
Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia.
Huayan
H
Zhao
Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China.
Shiyou
S
Lü
Institute for Integrative Genome Biology, Center for Plant Cell Biology & Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA.
Ruixi
R
Li
Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia.
Tao
T
Chen
Bioscience Core Lab, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia.
Huoming
H
Zhang
Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia.
Peng
P
Cui
Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia.
Feng
F
Ding
Department of Biology, Hong Kong Baptist University, Hong Kong, P. R. China.
Pei
P
Liu
Bioscience Core Lab, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia.
Guangchao
G
Wang
Department of Biology, Hong Kong Baptist University, Hong Kong, P. R. China.
Yiji
Y
Xia
Department of Biology, University of Louisville, Louisville, KY 40292, USA.
Mark P
MP
Running
Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia liming.xiong@kaust.edu.sa.
Liming
L
Xiong
D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000378:metabolism*; D009154:Mutation; D010937:Plant Growth Regulators / Q000378:metabolism*; D012269:Ribosomal Proteins / Q000235:genetics* / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism*
D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; C000602136:LSG1-2 protein, Arabidopsis; D010937:Plant Growth Regulators; D012269:Ribosomal Proteins
Arabidopsis; AtLSG1; auxin homeostasis; expression pattern; map-based cloning; proteomics; ribosome biogenesis.