ABSTRACT
Partial mycoheterotrophic i.e., mixotrophic, plants are the species which partially depend on mycorrhizal fungi for its nutrients. Although some of these plants are known to show plasticity in the degree of fungal dependence induced by the changes in light condition, the genetic background of this plasticity is largely unsolved. Here, we investigated the relationships between environmental conditions and nutrient sources based on 13C and 15N enrichment in mixotrophic orchid Cymbidium goeringii. We also shaded them for 2 months and evaluated the effect of light condition on the nutrient sources based on the abundance of 13C and 15N and the gene expressions by RNA-seq based de novo assembly. The shading had no effect on isotope enrichment, possibly because of the translocation of carbon and nitrogen from the storage organs. Gene expression analysis showed the upregulation of genes involved in jasmonic acid response in leaves of the shaded plants, which suggests that the jasmonic acid played an important role in regulation of degree of dependence against the mycorrhizal fungi. Our results suggest that mixotrophic plants might be controlling their dependency against the mycorrhizal fungi by a common mechanism with the autotrophic plants.
Acknowledgments
This work is supported in part by the Ichimura Foundation for New Technology. Computations for the RNA-seq were performed on the NIG supercomputer at ROIS National Institute of Genetics. We thank Dr. Hiroshi Yura for supporting the sampling at the Ecological Garden of the Natural History Museum and Institute, Chiba.
Disclosure statement
No potential conflict of interest was reported by the author(s).
Supplementary material
Supplemental data for this article can be accessed online at https://doi.org/10.1080/15592324.2023.2180159