Stochastic inoculum, biotic filtering and species-specific seed transmission shape the rare imcrobiome of plants

A plant’s health and productivity is influenced by its associated microbes. Although the common/core microbiome is often thought to be the most influential, significant numbers of rare or uncommon microbes (e.g., specialized endosymbionts) may also play an important role in the health and productivity of certain plants in certain environments. To help identify rare/specialized bacteria and fungi in the most important angiosperm plants, we contrasted microbiomes of the seeds, spermospheres, shoots, roots and rhizospheres of Arabidopsis, Brachypodium, maize, wheat, sugarcane, rice, tomato, coffee, common bean, cassava, soybean, switchgrass, sunflower, Brachiaria, barley, sorghum and pea. Plants were grown inside sealed jars on sterile sand or farm soil. Seeds and spermospheres contained some uncommon bacteria and many fungi, suggesting at least some of the rare microbiome is vertically transmitted. About 95% and 86% of fungal and bacterial diversity inside plants was uncommon; however, judging by read abundance, uncommon fungal cells are about half of the mycobiome, while uncommon bacterial cells make up less than 11% of the microbiome. Uncommon-seed-transmitted microbiomes consisted mostly of Proteobacteria, Firmicutes, Bacteriodetes, Ascomycetes and Basidiomycetes, which most heavily colonized shoots, to a lesser extent roots, and least of all, rhizospheres. Soil served as a more diverse source of rare microbes than seeds, replacing or excluding the majority of the uncommon-seed-transmitted microbiome. With the rarest microbes, their colonization pattern could either be the result of stringent biotic filtering by most plants, or uneven/stochastic inoculum distribution in seeds or soil. Several strong plant–microbe associations were observed, such as seed transmission to shoots, roots and/or rhizospheres of Sarocladium zeae (maize), Penicillium (pea and Phaseolus), and Curvularia (sugarcane), while robust bacterial colonization from cassava field soil occurred with the cyanobacteria Leptolyngbya into Arabidopsis and Panicum roots, and Streptomyces into cassava roots. Some abundant microbes such as Sakaguchia in rice shoots or Vermispora in Arabidopsis roots appeared in no other samples, suggesting that they were infrequent, stochastically deposited propagules from either soil or seed (impossible to know based on the available data). Future experiments with culturing and cross-inoculation of these microbes between plants may help us better understand host preferences and their role in plant productivity, perhaps leading to their use in crop microbiome engineering and enhancement of agricultural production

NYMPHSTAR: an accurate high-throughput quantitative method for whitefly (Aleurotrachelus socialis Bondar) resistance phenotyping in cassava

Whitefly (Aleurotrachelus socialis Bondar) is an important pest causing high economic losses in cassava production systems in the north of South America. It reduces the plant’s photosynthesis by colonizing the cassava leaves and either directly feeding on their phloem sap or excreting substances that allow the growth of sooty mold and the consequent reduction of the photosynthetic area. The deployment of the crop’s natural resistance to this pest is the most effective approach to its management. Phenotypic evaluation to identify germplasm with superior whitefly-resistance (WFR) levels from that showing a whitefly susceptible (WFS) response will benefit from the availability of an accurate high-throughput, quantitative phenotyping method

T2-B Hacia la resistencia a mosca blanca en yuca (Manihot Esculenta, Crantz): Multiomicas como estraegia para encontrar marcadores.

Las moscas blancas ( son el principal estrés biótico que amenaza la sostenibilidad del cultivo de la yuca, causando daños directos debido a la alimentación y puede destruir el cultivo La especie más importante en América Latina es Aleurotrachelus socialis Uno de los mecanismos de resistencia más potentes a WF fue descubierto en el CIAT Para desentrañar el mecanismo de resistencia a WF y definir las regiones genéticas involucradas en la respuesta resistente contra el ataque de A socialis propusimos adoptar los enfoques ómicos mapeo QTL Quantified trait Loci), y Metabolómica para identificar la base genética de la resistencia cuantitativa de la yuca a WF utilizando una población de segregantes entre ECU 72 x COL 2246 (CM 8996 El mapa de ligamiento de alta resolución de esta población fue la base para el mapeo QTL para el rasgo de conteo de ninfas con datos de resistencia recopilados para la familia de segregación recopilados a través de 5 experimentos de fenotipado realizados durante cuatro años 2013 2016 2017 y 2018)