Cytokinin-deficient Chlamydomonas reinhardtii CRISPR-Cas9 mutants show reduced ability to prime resistance of tobacco against bacterial infection

0585950 - ÚVGZ 2025 RIV US eng J - Journal Article
Sándor, Roman - Wagh, Sopan - Kelterborn, S. - Grosskinsky, D. K. - Novák, Ondřej - Olsen, N. - Paul, B. - Petřík, Ivan - Wu, S. - Hegemann, P. - Strnad, Miroslav - Červený, Jan - Roitsch, Thomas
Cytokinin-deficient Chlamydomonas reinhardtii CRISPR-Cas9 mutants show reduced ability to prime resistance of tobacco against bacterial infection.
Physiologia Plantarum. Roč. 176, č. 3 (2024), č. článku e14311. ISSN 0031-9317. E-ISSN 1399-3054
R&D Projects: GA ČR(CZ) GA21-07661S; GA TA ČR(CZ) TN02000044; GA ČR(CZ) GA18-24397S
Institutional support: RVO:86652079 ; RVO:61389030
Keywords : plant-growth * pseudomonas-syringae * endogenous cytokinins * chlorella-fusca * abscisic-acid * cyanobacteria * biosynthesis * auxin * microalgae * immunity
OECD category: Plant sciences, botany; Plant sciences, botany (UEB-Q)
Impact factor: 6.4, year: 2022
Method of publishing: Open access
https://onlinelibrary.wiley.com/doi/10.1111/ppl.14311

Although microalgae have only recently been recognized as part of the plant and soil microbiome, their application as biofertilizers has a tradition in sustainable crop production. Under consideration of their ability to produce the plant growth-stimulating hormone cytokinin (CK), known to also induce pathogen resistance, we have assessed the biocontrol ability of CK-producing microalgae. All pro- and eukaryotic CK-producing microalgae tested were able to enhance the tolerance of tobacco against Pseudomonas syringae pv. tabaci (PsT) infection. Since Chlamydomonas reinhardtii (Cre) proved to be the most efficient, we functionally characterized its biocontrol ability. We employed the CRISPR-Cas9 system to generate the first knockouts of CK biosynthetic genes in microalgae. Specifically, we targeted Cre Lonely Guy (LOG) and isopentenyltransferase (IPT) genes, the key genes of CK biosynthesis. While Cre wild-type exhibits a strong protection, the CK-deficient mutants have a reduced ability to induce plant defence. The degree of protection correlates with the CK levels, with the IPT mutants showing less protection than the LOG mutants. Gene expression analyses showed that Cre strongly stimulates tobacco resistance through defence gene priming. This study functionally verifies that Cre primes defence responses with CK, which contributes to the robustness of the effect. This work contributes to elucidate microalgae-mediated plant defence priming and identifies the role of CKs. In addition, these results underscore the potential of CK-producing microalgae as biologicals in agriculture by combining biofertilizer and biocontrol ability for sustainable and environment-friendly crop management.
Permanent Link: https://hdl.handle.net/11104/0353585