TY - JOUR
T1 - The effect of exogenous nitrate on LCO signalling, cytokinin accumulation, and nodule initiation in Medicago truncatula
AU - Gühl, Kerstin
AU - Holmer, Rens
AU - Xiao, Ting Ting
AU - Shen, Defeng
AU - Wardhani, Titis A.K.
AU - Geurts, René
AU - van Zeijl, Arjan
AU - Kohlen, Wouter
N1 - KAUST Repository Item: Exported on 2021-07-16
Acknowledgements: This work was supported by NWO-VICI (865.13.001) to R.G and NWO-VENI (863.15.010) to W.K.
PY - 2021/6/28
Y1 - 2021/6/28
N2 - Nitrogen fixation by rhizobia is a highly energy-demanding process. Therefore, nodule initiation in legumes is tightly regulated. Environmental nitrate is a potent inhibitor of nodulation. However, the precise mechanism by which this agent (co)regulates the inhibition of nodulation is not fully understood. Here, we demonstrate that in Medicago truncatula the lipo-chitooligosaccharideinduced accumulation of cytokinins is reduced in response to the application of exogenous nitrate. Under permissive nitrate conditions, perception of rhizobia-secreted signalling molecules leads to an increase in the level of four cytokinins (i.e., iP, iPR, tZ, and tZR). However, under high-nitrate conditions, this increase in cytokinins is reduced. The ethylene-insensitive mutant Mtein2/sickle, as well as wild-type plants grown in the presence of the ethylene biosynthesis inhibitor 2-aminoethoxyvinyl glycine (AVG), is resistant to the inhibition of nodulation by nitrate. This demonstrates that ethylene biosynthesis and perception are required to inhibit nodule organogenesis under high-nitrate conditions.
AB - Nitrogen fixation by rhizobia is a highly energy-demanding process. Therefore, nodule initiation in legumes is tightly regulated. Environmental nitrate is a potent inhibitor of nodulation. However, the precise mechanism by which this agent (co)regulates the inhibition of nodulation is not fully understood. Here, we demonstrate that in Medicago truncatula the lipo-chitooligosaccharideinduced accumulation of cytokinins is reduced in response to the application of exogenous nitrate. Under permissive nitrate conditions, perception of rhizobia-secreted signalling molecules leads to an increase in the level of four cytokinins (i.e., iP, iPR, tZ, and tZR). However, under high-nitrate conditions, this increase in cytokinins is reduced. The ethylene-insensitive mutant Mtein2/sickle, as well as wild-type plants grown in the presence of the ethylene biosynthesis inhibitor 2-aminoethoxyvinyl glycine (AVG), is resistant to the inhibition of nodulation by nitrate. This demonstrates that ethylene biosynthesis and perception are required to inhibit nodule organogenesis under high-nitrate conditions.
UR - http://hdl.handle.net/10754/670231
UR - https://www.mdpi.com/2073-4425/12/7/988
UR - http://www.scopus.com/inward/record.url?scp=85109292039&partnerID=8YFLogxK
U2 - 10.3390/genes12070988
DO - 10.3390/genes12070988
M3 - Article
C2 - 34203444
SN - 2073-4425
VL - 12
SP - 988
JO - Genes
JF - Genes
IS - 7
ER -