Research
Ongoing Projects
The above figure depicts the morphology of wild emmer wheat in its natural habitat, upper Galilee, Israel, with immature (A) and mature (B) disarticulating spikes.
Dissection of the molecular mechanisms of broad-spectrum resistance conferred byPmG3M to wheat powdery mildew
Cloning the PmG3M gene can provide a better understanding of the evolution and mechanisms of resistance of wild emmer wheat populations against powdery mildew. Deployment of effective powdery mildew resistance genes (Pm genes) is a sustainable and economical approach to reduce yield losses caused by this pathogen. The efforts toward this goal will result in the mapping and cloning of PmG3M and deploy it in the bread wheat breeding program.
Related research publications:
1. Li, Yinghui, Zhen-Zhen Wei, Andrii Fatiukha, Samidha Jaiwar, Hanchao Wang, Samiha Hasan, Zhiyong Liu, Hanan Sela, Tamar Krugman, and Tzion Fahima. "TdPm60 identified in wild emmer wheat is an ortholog of Pm60 and constitutes a strong candidate for PmG16 powdery mildew resistance." Theoretical and Applied Genetics 134, no. 9 (2021): 2777-2793. https://link.springer.com/article/10.1007/s00122-021-03858-3
2. Zhang, Qiang1, Yinghui Li1, Yiwen Li, Tzion Fahima, Qian-Hua Shen, and Chaojie Xie. "Introgression of the Powdery Mildew Resistance Genes Pm60 and Pm60b from Triticum urartu to Common Wheat Using Durum as a ‘Bridge’." Pathogens 11, no. 1 (2022): 25 (IF=3.492). (Co-First Author, Co-corresponding author) https://www.mdpi.com/2076-0817/11/1/25
3. Yinghui Li, Lina Qiu, Xinye Liu, Qiang Zhang, Xiangxi Zhuansun, Huifang Li, Xin Chen, Tamar Krugman, Tzion Fahima, Qixin Sun, Chaojie Xie*. Glycerol induced powdery mildew resistance in wheat by regulating plant fatty acid metabolism, plant hormones cross-talk, and pathogenesis-related genes. International Journal of Molecular Science (IF= 5.923). 2020, 21(2), p.673. https://www.mdpi.com/1422-0067/21/2/673
Developing a Genetic transformation model system for investigation of disease resistance mechanism in wheat
The objective of the research is to develop a wheat transformation system for studying plant immunity mechanisms and dissect the molecular plant-pathogen interactions. This research will focus on using diploid (Triticum monococcum), tetraploid (Triticum turgidum var. durum) and hexaploid (Triticum aestivum) wheat as model for genetic transformation. The use of a diploid model will allow reducing the complexity of the work involved when studying hexaploid wheat. This high effective transformation system of wheat will be established and enable to develop a model for studying Triticeae biology, genomics, and proteomics.
Immature embryos ready for transformation
Co-cultivation with agrobacterium and target gene
Wheat leaf segments at 14 dpi in NILs (the susceptible wild-type Kronos and the resistant transgenic Kronos+Wtk1) infected with Pst isolate #5006, race 38E134.
Puccinia striiformis f. sp. tritici (isolate #5006, race 38E134) after incubation for 24 h on agar solid medium in humidity chamber. (a) spores; (b) germ tubes
Characterization of the immune signaling network that activates the resistance mechanism conferred by WTK1
The aim of this particular project is to scrutinize the role of wheat tandem kinase 1 (WTK1) in the immune signaling network that activates this resistance mechanism and investigate the mechanisms of wheat-pathogen interactions. The object of this work is wheat which is a staple food in many countries, but its production is hampered by a lot of biotic and abiotic factors. One of them is the fungal pathogen Puccinia striiformis f.sp. tritici (Pst) that causes stripe rust diseases of cereals. The most cost-effective and environmentally friendly solution to this problem is to use genetically resistant cultivars that harbor disease resistance genes (R-genes such as Yr15). Yr15 was cloned by our lab (Fahima’s lab) in 2018. This gene was found to encode a protein with a tandem kinase-pseudokinase domain architecture designated as WTK1. The pivotal aim is to find out what is the role of WTK1 in the resistance mechanism of wheat. To study this, we will use several approaches: one of them is RNA-seq. The result of this analysis will be a list of candidate proteins that are partners of WTK1 or belong to its signaling pathway. Further, we will validate the WTK1 candidate proteins list using CRISPR-Cas9 gene-editing technology.
Natural variation and epistatic effects of gene(s) associated with root development in wheat
The main objective of this research is to verify the candidate genes (OPR6 genes) on the chromosome arm 1BS that regulate the root length, and identify a QTL on chromosome arm 4BL which modulate activity of the candidate genes in 1BS chromosome arm, and provide a better understanding of root architectures to the breeders to select the good genotypes with suitable root architecture.
Related research publication
Gabay, G., J. Zhang, G.F. Burguener, T. Howell, H. Wang, T. Fahima, A. Lukaszewski, J.I. Moriconi, G.E. Santa Maria, and J. Dubcovsky, "Structural rearrangements in wheat (1BS)-rye (1RS) recombinant chromosomes affect gene dosage and root length."
Plant Genome. 2021;14:e20079
https://acsess.onlinelibrary.wiley.com/doi/epdf/10.1002/tpg2.20079
Cultivated wheat infected with stripe rust
Protoplast
Identification of fungal effector(s) of Stripe Rust recognized by WTK1 in wheat
Plants are an essential part of worldwide food production. Wheat plays the leading role here; it ranks first in world production. Unfortunately, the wheat crop suffers significant losses due to various pathogens and pests. An urgent task is to create a new breeding material resistant to multiple harmful organisms. Rust fungi constitute the largest group of fungal pathogens of plants, with more than 7000 species described. One of the most destructive wheat diseases is Stripe Rust (yellow rust) caused by Puccinia striiformis f.sp. tritici (Pst). Nowadays, the primary way to control it is to treat the plantings with fungicides. It takes billions of dollars and causes pollution of fertile soils worldwide. The most effective and environmentally friendly solution for moving away from chemically treated crops is growing resistant cultivars. Plants have various extracellular and intracellular receptors capable of recognizing the presence of a pathogen and eliciting immune responses. Exploiting major race-specific resistance (R) genes in wheat varieties is a productive strategy for disease management, but new virulent Pst races that break these resistance genes are rapidly evolving. Therefore, the most interesting is genes provide broad-spectrum resistance. Such as, the Yr15 gene, which encodes a kinase-pseudokinase protein, was effective against more than 3000 genetically and geographically diverse Pst isolates. Therefore, a study of plant resistance genes against this disease and signaling pathways is an important and pressing issue for the protection of wheat production around the world.
Fielder - susceptible to Yellow rust
Resistant to Yellow rust
Triticum monococcum accession
Identifying and mapping new Powdery mildew and Yellow rust resistant genes using Tritium monococcum as a gene source
This project focuses on screening more than 100 wheat accessions of Tritium monococcum, which is a good source for resistant genes. A segregating population will be developed by crossing the resistant accession with the susceptible accession Further, by using molecular markers gene mapping will be done.
TKP Protein Family
The Yr15 resistance gene is derived from wild emmer wheat (Triticum dicoccoides, accession G25) confers broad-spectrum resistance against Pst demonstrated to be effective against more than 3000 genetically and geographically diverse Pst isolates. The team led by Prof. Fahima has cloned Yr15 encoding a protein with a tandem kinase-pseudokinase domain architecture and designated it as Wheat Tandem Kinase 1 (WTK1) (Klymiuk et al., 2018, 2019). The occurrence of functional resistance genes with a tandem kinase structure, as well as of many WTK1 orthologs and paralogs in wheat and its near relatives, motivated us to search for similar protein architectures across the plant kingdom. Altogether, we found 92 predicted proteins that are composed of putative kinase and pseudokinase domains in tandem; like WTK1, none had additional conserved domains. Most of the putative kinase domains share key conserved residues, while the putative pseudokinase domains are generally highly divergent in these positions, suggesting that they probably have no or impaired kinase activity. The phylogenetic analysis showed that all 184 putative kinase and pseudokinase domains of the 92 predicted proteins could be sorted into 11 major clades and two singletons.
