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Lotus SHAGGY‐like kinase 1 is required to suppress nodulation in Lotus japonicus
Author(s) -
Garagounis Constantine,
Tsikou Daniela,
Plitsi Panagiota K.,
Psarrakou Ioanna S.,
Avramidou Marianna,
Stedel Catalina,
Anagnostou Maria,
Georgopoulou Maria E.,
Papadopoulou Kalliope K.
Publication year - 2019
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.14207
Subject(s) - lotus japonicus , lotus , biology , microbiology and biotechnology , mutant , gene , phenotype , root nodule , signal transduction , kinase , sinorhizobium meliloti , genetics , symbiosis , botany , bacteria
Summary Glycogen synthase kinase/SHAGGY‐like kinases ( SK s) are a highly conserved family of signaling proteins that participate in many developmental, cell‐differentiation, and metabolic signaling pathways in plants and animals. Here, we investigate the involvement of SK s in legume nodulation, a process requiring the integration of multiple signaling pathways. We describe a group of SK s in the model legume Lotus japonicus ( LSK s), two of which respond to inoculation with the symbiotic nitrogen‐fixing bacterium Mesorhizobium loti . RNA i knock‐down plants and an insertion mutant for one of these genes, LSK 1 , display increased nodulation. Ηairy‐root lines overexpressing LSK 1 form only marginally fewer mature nodules compared with controls. The expression levels of genes involved in the autoregulation of nodulation ( AON ) mechanism are affected in LSK 1 knock‐down plants at low nitrate levels, both at early and late stages of nodulation. At higher levels of nitrate, these same plants show the opposite expression pattern of AON ‐related genes and lose the hypernodulation phenotype. Our findings reveal an additional role for the versatile SK gene family in integrating the signaling pathways governing legume nodulation, and pave the way for further study of their functions in legumes.