Discipline of Biological Sciences, School of Natural Sciences, University of Tasmania, Private Bag 55, Hobart, Tasmania 7001, Australia.
Enza Zaden Australia, 218 Eumungerie Road, Narromine, NSW 2821, Australia.
Plant Cell Physiol. 2024 Jan 19;65(1):107-119. doi: 10.1093/pcp/pcad124.
Symbioses with beneficial microbes are widespread in plants, but these relationships must balance the energy invested by the plants with the nutrients acquired. Symbiosis with arbuscular mycorrhizal (AM) fungi occurs throughout land plants, but our understanding of the genes and signals that regulate colonization levels is limited, especially in non-legumes. Here, we demonstrate that in tomato, two CLV3/EMBRYO-SURROUNDING REGION (CLE) peptides, SlCLE10 and SlCLE11, act to suppress AM colonization of roots. Mutant studies and overexpression via hairy transformation indicate that SlCLE11 acts locally in the root to limit AM colonization. Indeed, SlCLE11 expression is strongly induced in AM-colonized roots, but SlCLE11 is not required for phosphate suppression of AM colonization. SlCLE11 requires the FIN gene that encodes an enzyme required for CLE peptide arabinosylation to suppress mycorrhizal colonization. However, SlCLE11 suppression of AM does not require two CLE receptors with roles in regulating AM colonization, SlFAB (CLAVATA1 ortholog) or SlCLV2. Indeed, multiple parallel pathways appear to suppress mycorrhizal colonization in tomato, as double mutant studies indicate that SlCLV2 and FIN have an additive influence on mycorrhizal colonization. SlCLE10 appears to play a more minor or redundant role, as cle10 mutants did not influence intraradical AM colonization. However, the fact that cle10 mutants had an elevated number of hyphopodia and that ectopic overexpression of SlCLE10 did suppress mycorrhizal colonization suggests that SlCLE10 may also play a role in suppressing AM colonization. Our findings show that CLE peptides regulate AM colonization in tomato and at least SlCLE11 likely requires arabinosylation for activity.
共生体与有益微生物在植物中广泛存在，但这些关系必须平衡植物投入的能量与获得的营养物质。与丛枝菌根（AM）真菌的共生关系存在于整个陆地植物中，但我们对调节定植水平的基因和信号的理解是有限的，特别是在非豆科植物中。在这里，我们证明在番茄中，两种 CLV3/胚周围区域（CLE）肽，SlCLE10 和 SlCLE11，作用于抑制 AM 对根的定植。突变研究和毛状转化的过表达表明，SlCLE11 在根中局部作用以限制 AM 的定植。事实上，SlCLE11 在 AM 定植的根中强烈诱导表达，但 SlCLE11 不是磷酸盐抑制 AM 定植所必需的。SlCLE11 需要 FIN 基因，该基因编码一种用于 CLE 肽阿拉伯糖基化的酶，以抑制菌根定植。然而，SlCLE11 对 AM 的抑制不需要两个在调节 AM 定植中起作用的 CLE 受体，SlFAB（CLAVATA1 同源物）或 SlCLV2。事实上，多项平行途径似乎在番茄中抑制菌根定植，因为双突变体研究表明 SlCLV2 和 FIN 对菌根定植有累加影响。SlCLE10 似乎发挥了较小或冗余的作用，因为 cle10 突变体对根内 AM 定植没有影响。然而，cle10 突变体有更多的菌丝体和异位过表达 SlCLE10 确实抑制菌根定植的事实表明，SlCLE10 也可能在抑制 AM 定植中发挥作用。我们的研究结果表明，CLE 肽在番茄中调节 AM 定植，至少 SlCLE11 可能需要阿拉伯糖基化才能发挥活性。
