Knockout of Diguanylate Cyclase Genes in Lysobacter enzymogenes to Improve Production of Antifungal Factor and Increase Its Application in Seed Coating

Clp is a “busy” transcription factor in the bacterial warrior, Lysobacter enzymogenes

“…4 ) [54] . This biochemical finding is consistent with our observation that elevated levels of c-di-GMP inhibit HSAF biosynthesis [56] . According to our earlier report, Clp can also respond to two small molecules to fine-tune HSAF production.…”

Coordinated control of the type IV pili and c‐di‐GMP‐dependent antifungal antibiotic production in Lysobacter by the response regulator PilR

“…Because PilR was shown earlier to decrease c‐di‐GMP concentration, we hypothesized that it either represses expression of a DGC gene or activates expression of a PDE gene. To test this hypothesis, we investigated PilR binding to promoter regions of 10 putative DGC genes as well as two PDE genes ( lchP and rpfG ) previously shown by us to affect c‐di‐GMP concentration under the experimental conditions used (Figure 1a) (Ren et al., 2020; Xu et al., 2018). The screen involving a bacterial one‐hybrid (B1H) system revealed that PilR binds to a single region (P LchD ) upstream of the le3756 gene, which we named lchD (Figure 1b).…”

“…The PilR-His -P LchD -2a complex could be competitively inhibited to some extent by the unlabelled probe provided F I G U R E 1 PilR binds upstream of the lchD gene. (a) Schematic presentation of 10 active diguanylate cyclases (DGCs) and two active c-di-GMP-specific phosphodiesterases (PDEs) containing GGDEF, EAL, or HD-GYP domains encoded in the Lysobacter enzymogenes OH11 genome (Ren et al, 2020;Xu et al, 2018). The promoter regions of the indicated length are indicated.…”

“…It is broken down by c‐di‐GMP‐specific phosphodiesterases (PDEs) that contain EAL (Christen et al., 2005; Schmidt et al., 2005; Tamayo et al., 2005) or HD‐GYP (Bellini et al., 2014) catalytic domains. The genome of L. enzymogenes OH11 encodes 26 GGDEF, EAL, or HD‐GYP domain proteins presumably involved in c‐di‐GMP synthesis or degradation (Ren et al., 2020). Three of these proteins, RpfG, LchP (both PDEs), and WspR (a DGC), regulate HSAF biosynthesis (Han et al., 2015; Xu et al., 2018, 2021) by means of two c‐di‐GMP‐binding protein effectors, Clp and CdgL (Han et al., 2020; Xu et al., 2018).…”

Antifungal weapons of Lysobacter, a mighty biocontrol agent

“…The Qian group also produces a third product, HSAF‐containing seed coating. Under laboratory conditions, it shows 75%–80% antifungal activity against the maize seed‐borne filamentous pathogen, Pythium gramincola (Ren et al ., 2020). While applications of HSAF have so far been relatively limited, the breadth of its inhibitory activities against fungal pathogens of various agricultural crops is encouraging.…”