Morphological and Transcriptional Characteristics of the Symbiotic Interaction between Pinus massoniana and Suillus bovinus

Abstract

Ectomycorrhiza (ECM) function has been well studied; however, there is little detailed information regarding the establishment of ECM symbioses. We investigated the morphological and transcriptional changes that occur during the establishment of the Pinus massoniana–Suillus bovinus ECM. S. bovinus promoted the growth of P. massoniana via the release of volatile organic compounds and exudates during the pre-symbiotic stage. Exudate-induced effects showed host plant specificity. At seven days post-inoculation (dpi), the mycelium started to penetrate P. massoniana roots. At 28 dpi, the Hartig net and mantle formed. At the pre-symbiotic stage, most differentially expressed genes in P. massoniana roots were mapped to the biosynthesis of secondary metabolites, signal transduction, and carbohydrate metabolism. At the symbiotic stage, S. bovinus colonization induced the reprogramming of pathways involved in genetic information processing in P. massoniana, particularly at the Hartig net and mantle formation stage. Phenylpropanoid biosynthesis was present at all stages and was regulated via S. bovinus colonization. Enzyme inhibitor tests suggested that hydroxycinnamoyl-CoA shikimate/quinate transferase is involved in the development of the Hartig net. Our findings outline the mechanism involved in the P. massoniana–S. bovinus ECM. Further studies are needed to clarify the role of phenylpropanoid biosynthesis in ECM formation.

Establishment of Pinus massoniana–Lactarius hatsudake Symbiosis

“…The total root length, surface area, average diameter, root volume, and number of root tips of mycorrhizal seedlings were higher than those of non-mycorrhizal seedlings under aluminum stress [46]. Feng et al found that volatile organic compounds (VOCs) and exudates released by Suillus bovinus, an EMF, could significantly promote the development of the roots of P. massoniana [35]. It has been shown that the ectomycorrhizal fungus Laccaria bicolor stimulates lateral root formation through auxin transport signaling [47].…”

“…The morphological characters of ectomycorrhizae were observed and photographed under a stereomicroscope (S8APO, Leica Microsytems, Germany). Anatomical cross sections were prepared from fresh root material and followed by treatments according to methods described in a previous study with minor modifications [35]: the root tips of P. massoniana were sampled and embedded in agarose water solution for solidification. Then, root samples were sliced in a shaking microtome and placed in a 10% KOH solution at 90 • C for 30 min of transparency.…”

Morphogenesis and metabolomics reveal the compatible relationship among Suillus bovinus , Phialocephala fortinii , and their co-host, Pinus massoniana

“…fortinii mycelium began to invade the root system of Asparagus officinalis at 9 dpi; however, the formation of microsclerotia was observed only after 2 months. Moreover, the experimental system and culture environment may also affect the time needed for symbiont formation ( 42 ).…”

Bioassay-guided isolation of three new alkaloids from Suillus bovinus and preliminary mechanism against ginseng root rot

“…Suillus bovinus , an edible mushroom belonging to the Suillus genus, is broadly distributed across various regions globally ( Feng et al, 2022 ). In recent years, research about S. bovinus focus mainly on the mechanisms related to symbiotic interactions with trees ( Sun et al, 2023 ).…”