c; 108 CFU/mouse

Athymic Nude mice were subcutaneously implanted with HCT116 colon tumor

Harvested tumors from animals of all experimental groups contained similar numbers of viable bacteria (∼109 CFU/g of tumor) irrespective of the strain administered to the mice (Fig. S8).

This dichotomy between soil chemical stressors and drought potentially points to two distinct molecular syndromes driving the ecological strategies plants use to regulate AM symbiosis during persistent stress lasting years/decades versus seasonal/episodic stress (see Supplementary Text).

We found plants disproportionately target larger AM-expanded gene families for context-dependent regulation under soil chemical stress, with 200%, 86%, and 41% greater context-dependent expression of these gene families than expected by chance in response to low phosphorus, low potassium, and high salinity stress, respectively (p = 0.0006, p = 0.0054, and p = 0.0297; Fig. 3a), indicating the gene expression plasticity facilitated by gene family expansions is important for context-dependent regulation under soil chemical stress.

As environments worldwide change at unprecedented rates during the Anthropocene, understanding context-dependency – how species regulate interactions to match changing environments – is crucial. However, generalizable molecular mechanisms underpinning context-dependency remain elusive. Combining comparative genomics across 42 angiosperms with transcriptomics, genome-wide association mapping, and gene duplication origin analyses, we show for the first time that gene family expansions undergird context-dependent regulation of species interactions. Gene families expanded in mycorrhizal fungi-associating plants display up to 200% more context-dependent gene expression and double the genetic variation associated with mycorrhizal benefits to plant fitness. Moreover, we discover these gene family expansions arise primarily from tandem duplications with >2-times more tandem duplications genome-wide, indicating gene family expansions continuously supply genetic variation allowing fine-tuning of context-dependency in species interactions throughout plant evolution.

protocod

Here we demonstrate that the Cas7-11 proteins are modular and can be engineered into compact, efficient, and highly specific Cas7-S effectors for RNA-targeting applications.

We also found Cas7-1 contains a conserved catalytic residue that aligns to all known Cas7.3 domains, as well as zinc-finger motifs unique to type III-E effectors (4) (Figure 1B-E). Lastly, the Cas1 domain aligns to a Reverse Transcriptase-Cas1 (RT-Cas1) fusion protein commonly associated with type III systems of all characterized subtypes (III-A, III-B, III-C, and III-D) (Figure 1F, File S1).