Caractérisation des miARN du nématode à kyste du soja : une première étape vers la validation des interactions inter-royaumes entre hôte et parasite

Citation

Ste-Croix, D.T., R.R. Bélanger, B. Mimee. 2023. Caractérisation des miARN du nématode à kyste du soja : une première étape vers la validation des interactions inter-royaumes entre hôte et parasite. Congrès annuel de la Société de Protection des Plantes du Québec, 19-20 octobre 2023, Montréal, QC.

Résumé en langage clair

The soybean cyst nematode (SCN), a major problem for soybean farming in North America, causes over $1.3 billion in losses each year. It uses special proteins to turn soybean roots into feeding structures called syncytia. Controlling these proteins is crucial for syncytium formation. One way they're controlled is through microRNAs (miRNAs), small molecules that regulate genes after they've been transcribed. These miRNAs might even be able to regulate genes across different species, a concept called cross-kingdom interaction. In a recent study, we examined the miRNA makeup of SCN. We looked at small RNAs from different stages of the nematode's development and found 121 miRNA locations from 96 families. Most of these miRNAs shared evolutionary roots within the Heteroderidae family, but some were unique to SCN. By using prediction tools, we identified potential miRNA targets in both the nematode and its soybean host. We also identified nine miRNAs that could potentially regulate genes across different species. This research sheds light on how miRNAs might play a role in the complex interaction between the soybean cyst nematode and soybean plants.

Résumé

The soybean cyst nematode (SCN), Heterodera glycines, represents the most significant threat to
soybean cultivation in North America, causing annual losses exceeding 1.3 billion U.S. dollars. This
nematode employs a sophisticated strategy, involving the secretion of various stylet-associated effector
proteins, to transform soybean root tissues into a highly active feeding structure known as the syncytium.
Precise control of effector expression is believed to be pivotal for the successful formation of this
syncytium. To date, various mechanisms have been proposed to regulate the expression of these
proteins, with post-transcriptional regulation being a prominent example. Specifically, microRNAs
(miRNAs), which typically consist of 20 to 22 nucleotide-long non-coding RNA molecules, are emerging
as a significant class of endogenous gene regulators that operate at the post-transcriptional level. These
small RNAs carry out their role by interacting with the 3' untranslated regions of genes leading to the
cleavage or the transcriptional repression of cognate mRNAs. Interestingly, there is also a hypothesis
suggesting that these same small RNAs might possess the capacity to transcend kingdom boundaries
and regulate genes in different species, a phenomenon known as cross-kingdom interaction. In the
present study, we undertook the task of characterizing the miRNome of the SCN. This was accomplished
by sequencing small RNAs isolated from whole nematodes and exosomes representing various
developmental stages. Our investigation led to the identification of 121 miRNA loci encompassing 96
distinct miRNA families. Interestingly, over 75% of newly discovered miRNAs demonstrated common
evolutionary roots within the Heteroderidae family, while the remaining newly identified candidates were
found exclusively in SCN. Furthermore, employing a combination of miRNA target prediction tools tailored
for both plants and animals, we compiled the first-ever repertoire of miRNA:mRNA interaction partners
within the nematode and its host plant. Additionally, we pinpointed a collection of nine potential
candidates for cross-kingdom miRNA regulation.

Date de publication

2023-10-19

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