Muhammad Syamsu Rizaludin

Muhammad Syamsu Rizaludin MSc

PhD Candidate


Droevendaalsesteeg 10
6708 PB Wageningen

+31 (0) 317 47 34 00

The Netherlands



The overall goal of my PhD project is to investigate the mechanisms underlying biotic-stress induced plant-microbe communication belowground via root-emitted volatile organic compounds (VOCs)


I am one of PhD students working in MiCrop consortium. Our focus is on understanding stress-adaptive microbiomes and their active recruitment by plants across the plant kingdom through a phylogenetic approach. We will zoom in on the discovery of novel microbiome functions that are recruited by plants to alleviate environmental stress. In particular, my PhD project investigates the role of root volatiles on the recruitment of rhizosphere microbes by plants under biotic stress conditions.



Belangrijkste publicaties

  • Metabolites

    The Chemistry of Stress: Understanding the ‘Cry for Help’ of Plant Roots

    Muhammad Syamsu Rizaludin, Nejc Stopnisek, Jos M. Raaijmakers, and Paolina Garbeva
    Plants are faced with various biotic and abiotic stresses during their life cycle. To withstand these stresses, plants have evolved adaptive strategies including the production of a wide array of primary and secondary metabolites. Some of these metabolites can have direct defensive effects, while others act as chemical cues attracting beneficial (micro)organisms for protection. Similar to aboveground plant tissues, plant roots also appear to have evolved “a cry for help” response upon exposure to stress, leading to the recruitment of beneficial microorganisms to help minimize the damage caused by the stress. Furthermore, emerging evidence indicates that microbial recruitment to the plant roots is, at least in part, mediated by quantitative and/or qualitative changes in root exudate composition. Both volatile and water-soluble compounds have been implicated as important signals for the recruitment and activation of beneficial root-associated microbes. Here we provide an overview of our current understanding of belowground chemical communication, particularly how stressed plants shape its protective root microbiome
  • Microorganisms

    Impact of Cellulose-Rich Organic Soil Amendments on Growth Dynamics and Pathogenicity of Rhizoctonia solani

    Clocchiatti et al.,
    Cellulose-rich amendments stimulate saprotrophic fungi in arable soils. This may increase competitive and antagonistic interactions with root-infecting pathogenic fungi, resulting in lower disease incidence. However, cellulose-rich amendments may also stimulate pathogenic fungi with saprotrophic abilities, thereby increasing plant disease severity. The current study explores these scenarios, with a focus on the pathogenic fungus Rhizoctonia solani. Saprotrophic growth of R. solani on cellulose-rich materials was tested in vitro. This confirmed paper pulp as a highly suitable substrate for R. solani, whereas its performance on wood sawdusts varied with tree species. In two pot experiments, the effects of amendment of R. solani-infected soil with cellulose-rich materials on performance of beetroot seedlings were tested. All deciduous sawdusts and paper pulp stimulated soil fungal biomass, but only oak, elder and beech sawdusts reduced damping-off of beetroot. Oak sawdust amendment gave a consistent stimulation of saprotrophic Sordariomycetes fungi and of seedling performance, independently of the time between amendment and sowing. In contrast, paper pulp caused a short-term increase in R. solani abundance, coinciding with increased disease severity for beet seedlings sown immediately after amendment. However, damping-off of beetroot was reduced if plants were sown two or four weeks after paper pulp amendment. Cellulolytic bacteria, including Cytophagaceae, responded to paper pulp during the first two weeks and may have counteracted further spread of R. solani. The results showed that fungus-stimulating, cellulose-rich amendments have potential to be used for suppression of R. solani. However, such amendments require a careful consideration of material choice and application strategy
  • Molecules

    Exploring the Volatiles Released from Roots of Wild and Domesticated Tomato Plants under Insect Attack

    Ana Shein Lee Díaz*, Muhammad Syamsu Rizaludin *, Hans Zweers, Jos M. Raaijmakers, and Paolina Garbeva
    Plants produce volatile organic compounds that are important in communication and defense. While studies have largely focused on volatiles emitted from aboveground plant parts upon exposure to biotic or abiotic stresses, volatile emissions from roots upon aboveground stress are less studied. Here, we investigated if tomato plants under insect herbivore attack exhibited a different root volatilome than non-stressed plants, and whether this was influenced by the plant’s genetic background. To this end, we analyzed one domesticated and one wild tomato species, i.e., Solanum lycopersicum cv Moneymaker and Solanum pimpinellifolium, respectively, exposed to leaf herbivory by the insect Spodoptera exigua. Root volatiles were trapped with two sorbent materials, HiSorb and PDMS, at 24 h after exposure to insect stress. Our results revealed that differences in root volatilome were species-, stress-, and material-dependent. Upon leaf herbivory, the domesticated and wild tomato species showed different root volatile profiles. The wild species presented the largest change in root volatile compounds with an overall reduction in monoterpene emission under stress. Similarly, the domesticated species presented a slight reduction in monoterpene emission and an increased production of fatty-acid-derived volatiles under stress. Volatile profiles differed between the two sorbent materials, and both were required to obtain a more comprehensive characterization of the root volatilome. Collectively, these results provide a strong basis to further unravel the impact of herbivory stress on systemic volatile emissions.
  • The ISME journal

    Microbial volatiles mediate bacterial evolutionary dynamics

    Muhammad Syamsu Rizaludin , Paolina Garbeva, Mark Zwart, Jie Hu
    Many microorganisms produce and respond to a range of structurally and functionally diverse volatiles. Microbial volatiles originate from a broad range of biosynthetic pathways and therefore display highly diverse structural and functional variations [1]. Volatile compounds are not only emitted into the gas phase but they can also be released in the water phase and play an important role in long-distance microbial interactions in both aquatic and terrestrial environments. As microbial volatiles can diffuse rapidly in both gas and water phases, they mediate swift chemical interactions and are the first compounds to reach a target organism [2]. The ability of microorganisms to release and respond to volatile compounds has been overlooked for a long time, but the knowledge gained in recent years shows that volatile-mediated interactions range from mutualism to competition.

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