23 research outputs found
The genetic basis of plantsā battle against witchweeds: linking immune responses to distinct resistance mechanisms
Parasitic plants of the Striga species significantly damage cereals in sub-Saharan Africa. Current agricultural practices are insufficient to manage Striga infestation, necessitating sustainable approaches that harness natural resistance mechanisms. Mutinda et al. (2023) examined how different genotypes of sorghum plants resist Striga after it attacks their roots. By comparing transcriptomes, they found that sorghum activates its immune system, and molecular signatures probably associate with distinct resistance mechanisms. This study will inform the development of Striga-resistant sorghum varieties to ward off root parasitic plants
Investigating Host and Parasitic Plant Interaction by Tissue-Specific Gene Analyses on Tomato and Cuscuta campestris Interface at Three Haustorial Developmental Stages.
Parasitic weeds cause billions of dollars in agricultural losses each year worldwide. Cuscuta campestris (C. campestris), one of the most widespread and destructive parasitic plants in the United States, severely reduces yield in tomato plants. Reducing the spread of parasitic weeds requires understanding the interaction between parasites and hosts. Several studies have identified factors needed for parasitic plant germination and haustorium induction, and genes involved in host defense responses. However, knowledge of the mechanisms underlying the interactions between host and parasitic plants, specifically at the interface between the two organisms, is relatively limited. A detailed investigation of the crosstalk between the host and parasite at the tissue-specific level would enable development of effective parasite control strategies. To focus on the haustorial interface, we used laser-capture microdissection (LCM) with RNA-seq on early, intermediate and mature haustorial stages. In addition, the tomato host tissue that immediately surround the haustoria was collected to obtain tissue- resolution RNA-Seq profiles for C. campestris and tomato at the parasitism interface. After conducting RNA-Seq analysis and constructing gene coexpression networks (GCNs), we identified CcHB7, CcPMEI, and CcERF1 as putative key regulators involved in C. campestris haustorium organogenesis, and three potential regulators, SlPR1, SlCuRe1-like, and SlNLR, in tomatoes that are involved in perceiving signals from the parasite. We used host-induced gene silencing (HIGS) transgenic tomatoes to knock-down the candidate genes in C. campestris and produced CRISPR transgenic tomatoes to knock out candidate genes in tomatoes. The interactions of C. campestris with these transgenic lines were tested and compared with that in wild-type tomatoes. The results of this study reveal the tissue-resolution gene regulatory mechanisms at the parasitic plant-host interface and provide the potential of developing a parasite-resistant system in tomatoes
Recommended from our members
Developing Parasite-Resistant Systems in Tomatoes to Control Infestations of Cuscuta campestris
Unlike most autotrophic plants, parasitic plants evolved to have a heterotrophic lifestyle and to steal water and nutrients from their host through specialized parasitic organs, haustoria. Some species of parasitic angiosperms parasitize major crop plants, which causes severe agricultural losses and threatens food security in many regions. Understanding how host plants sense and resist parasitic plants not only reveals the underlying mechanisms of various resistance systems, but also provides the foundation for agricultural improvements. Chapter One of this dissertation reviews the current knowledge on how host plants perceive stem and root parasitic plants and utilize different pre-attachment and post-attachment defense responses to deter these parasites.Cuscuta species (dodders) are stem holoparasitic angiosperms, which lack functional leaves and roots. Cuscuta campestris (C. campestris) is one of the most broadly distributed Cuscuta species and has a wide host range, which includes many important vegetable and fruit crops. Domesticated tomato (Solanum lycopersicum) is one of the crop plants that are vulnerable to C. campestris and reduces 70% yield upon Cuscuta infestations. Understanding the molecular mechanism of C. campestris haustorium formation will assist in parasitic weed management and the development of parasitic plant-resistant crops. Chapter Two of this dissertation investigated the transcriptome of six C. campestris tissues and identiļ¬ed LATERAL ORGAN BOUNDARIES DOMAIN 25 (CcLBD25) as a critical regulator in haustorium development.
On the other hand, even though most cultivated tomatoes are usually susceptible to C. campestris, some specific Heinz hybrid tomato cultivars were discovered to be resistant to Cuscuta species. These tomato cultivars are used as a biocontrol method in the field, but the resistance mechanism remains unknown. Chapter Three of this dissertation dives into the underlying mechanism and genes involved in this lignin-based defense response. These resistant Heinz cultivars trigger post-attachment lignification in the stem cortex upon C. campestris infection.
Although some studies have identified factors required for parasitic plant haustorium induction as well as genes involved in host defense responses, the signals involved in haustorium development at specific developmental stages and tissue-resolution communication between host and parasite during the haustorium penetration process are largely unknown. Chapter Four of this dissertation focused on the interface between the host and parasite. C. campestris haustorial tissue and tomato host tissue immediately surrounding haustoria were collected by laser-capture microdissection (LCM) to obtain tissue-resolution RNA-Seq profiles. These profiles were used to identify key genes regulating haustorial development and host responses, and describes my attempt to validate the function of these genes.
Finally, Chapter Five summarizes the major discoveries of each research project and the potential of utilizing these findings in agriculture. This dissertation provides an overview of both haustorium development in C. campestris and defense response in tomato host plants. Therefore, this work will be of interest to academic researchers in plant biology and researchers interested in developing potential agricultural translational applications
Recommended from our members
Developing Parasite-Resistant Systems in Tomatoes to Control Infestations of Cuscuta campestris
Unlike most autotrophic plants, parasitic plants evolved to have a heterotrophic lifestyle and to steal water and nutrients from their host through specialized parasitic organs, haustoria. Some species of parasitic angiosperms parasitize major crop plants, which causes severe agricultural losses and threatens food security in many regions. Understanding how host plants sense and resist parasitic plants not only reveals the underlying mechanisms of various resistance systems, but also provides the foundation for agricultural improvements. Chapter One of this dissertation reviews the current knowledge on how host plants perceive stem and root parasitic plants and utilize different pre-attachment and post-attachment defense responses to deter these parasites.Cuscuta species (dodders) are stem holoparasitic angiosperms, which lack functional leaves and roots. Cuscuta campestris (C. campestris) is one of the most broadly distributed Cuscuta species and has a wide host range, which includes many important vegetable and fruit crops. Domesticated tomato (Solanum lycopersicum) is one of the crop plants that are vulnerable to C. campestris and reduces 70% yield upon Cuscuta infestations. Understanding the molecular mechanism of C. campestris haustorium formation will assist in parasitic weed management and the development of parasitic plant-resistant crops. Chapter Two of this dissertation investigated the transcriptome of six C. campestris tissues and identiļ¬ed LATERAL ORGAN BOUNDARIES DOMAIN 25 (CcLBD25) as a critical regulator in haustorium development.
On the other hand, even though most cultivated tomatoes are usually susceptible to C. campestris, some specific Heinz hybrid tomato cultivars were discovered to be resistant to Cuscuta species. These tomato cultivars are used as a biocontrol method in the field, but the resistance mechanism remains unknown. Chapter Three of this dissertation dives into the underlying mechanism and genes involved in this lignin-based defense response. These resistant Heinz cultivars trigger post-attachment lignification in the stem cortex upon C. campestris infection.
Although some studies have identified factors required for parasitic plant haustorium induction as well as genes involved in host defense responses, the signals involved in haustorium development at specific developmental stages and tissue-resolution communication between host and parasite during the haustorium penetration process are largely unknown. Chapter Four of this dissertation focused on the interface between the host and parasite. C. campestris haustorial tissue and tomato host tissue immediately surrounding haustoria were collected by laser-capture microdissection (LCM) to obtain tissue-resolution RNA-Seq profiles. These profiles were used to identify key genes regulating haustorial development and host responses, and describes my attempt to validate the function of these genes.
Finally, Chapter Five summarizes the major discoveries of each research project and the potential of utilizing these findings in agriculture. This dissertation provides an overview of both haustorium development in C. campestris and defense response in tomato host plants. Therefore, this work will be of interest to academic researchers in plant biology and researchers interested in developing potential agricultural translational applications
LATERAL ORGAN BOUNDARIES DOMAIN 25 functions as a key regulator of haustorium development in dodders
Recommended from our members
The secret of self-fertilizing plants: NIN-NAD1's role in symbiotic nitrogen fixation.
Recommended from our members