Dynamics in the Strawberry Rhizosphere Microbiome in Response to Biochar and Botrytis cinerea Leaf Infection

Abstract

Adding biochar, the solid coproduct of biofuel production, to peat can enhance strawberry growth, and disease resistance against the airborne fungal pathogen Botrytis cinerea. Additionally, biochar can induce shifts in the strawberry rhizosphere microbiome. However, the moment that this biochar-mediated shift occurs in the rhizosphere is not known. Further, the effect of an above-ground infection on the strawberry rhizosphere microbiome is unknown. In the present study we established two experiments in which strawberry transplants (cv. Elsanta) were planted either in peat or in peat amended with 3% biochar. First, we established a time course experiment to measure the effect of biochar on the rhizosphere bacterial and fungal communities over time. In a second experiment, we inoculated the strawberry leaves with B. cinerea, and studied the impact of the infection on the rhizosphere bacterial community. The fungal rhizosphere community was stabilized after 1 week, except for the upcoming Auriculariales, whereas the bacterial community shifted till 6 weeks. An effect of the addition of biochar to the peat on the rhizosphere microbiome was solely measured for the bacterial community from week 6 of plant growth onwards. When scoring the plant development, biochar addition was associated with enhanced root formation, fruit production, and postharvest resistance of the fruits against B. cinerea. We hypothesize that the bacterial rhizosphere microbiome, but also biochar-mediated changes in chemical substrate composition could be involved in these events. Infection of the strawberry leaves with B. cinerea induced shifts in the bacterial rhizosphere community, with an increased bacterial richness. This disease-induced effect was not observed in the rhizospheres of the B. cinerea-infected plants grown in the biochar-amended peat. The results show that an above-ground infection has its effect on the strawberry rhizosphere microbiome, changing the bacterial interactions in the root-substrate interface. This infection effect on the bacterial rhizosphere microbiome seems to be comparable to, but less pronounced than the effect of biochar-addition to the peat. The biological meaning of these observations needs further research, but this study indicates that biochar and an above-ground pathogen attack help the plant to recruit rhizosphere microbes that may aid them in their plant growth and health.

Enhancement of maize plant growth with inoculation of phosphate-solubilizing bacteria and biochar amendment in soil

“…Biochar made from sawdust feedstock has been reported to assist plant growth by improving soil physicochemical properties such as enhancing nutrient retention up to 59%, and nutrient content of plant, which was also observed in the sawdustamended soil of the current study which enhanced nutrient concentration in soil and plant than the control (Laghari et al 2016). Biochar addition widely enhances the potential of soil to boost plant growth as observed in the bagasse-and sawdust biochar-amended soil where the plant length was notably increased than control by increasing soil porosity (De Tender et al 2016;Mollinedo et al 2016). According to an estimate, more than 80% of rhizospheric bacteria can produce growth-promoting chemicals and increase in plant height which is endorsed in the PSB-inoculated plants in the current study by enhancement of root and shoot length, particularly the L. fusiformis-inoculated maize plant than the control (Arruda et al 2013).…”

Trichoderma-Inoculated Miscanthus Straw Can Replace Peat in Strawberry Cultivation, with Beneficial Effects on Disease Control

“…The raw sequence data is available in the NCBI Sequence Read Archive under the accession numbers PRJNA398479 and PRJNA398478 for the bacterial and fungal sequences, respectively. The sequence read processing is described in detail in De Tender et al ( 2016a , b ).…”

“…The analyses were done upon clustering the bacterial and fungal OTU tables on genus level. An extensive description of the normalization, empirical Bayes estimation and statistical tests performed can be found in De Tender et al ( 2016b ).…”

“…for biocontrol agents to grow (Hoitink and Boehm, 1999 ). Interest in understanding/engineering the biological properties of growing media and the corresponding rhizosphere microbiome is receiving increased attention (De Tender et al, 2016a , b ; Grunert et al, 2016 ).…”

The Impact of Soil-Applied Biochars From Different Vegetal Feedstocks on Durum Wheat Plant Performance and Rhizospheric Bacterial Microbiota in Low Metal-Contaminated Soil

“…In the last decade, biochar has been focused upon due to its great potential for climate change mitigation, and its application to soil has emerged as an attractive strategy for sequestering carbon, reducing greenhouse gas (GHG) emissions, and improving soil quality (Lehmann, 2007;Atkinson et al, 2010;Agegnehu et al, 2016). Biochar may have variable effects on (i) soil properties, (ii) soil biota, including microbiota (Lehmann et al, 2011), (iii) plant growth and crop yield (Biederman and Harpole, 2013;Jefferey et al, 2015;Pandit et al, 2018;Sun et al, 2019), (iv) roots (Brennan et al, 2014;Prendergast-Miller et al, 2014;Xiang et al, 2017) and the rhizosphere microbiome (De Tender et al, 2016;Kolton et al, 2017), and (v) crop resistance to disease (Elad et al, 2011;Frenkel et al, 2017). Biochar has also been proved to be effective in the remediation of soils with both heavy metal and organic pollutants (Brennan et al, 2014;Zama et al, 2018), playing a critical role in reducing ecological and human health risks associated with heavy metal contamination.…”