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Pathogenesis-related (PR) genes are useful molecular markers, and gene expressions are activated in the reaction of plant-parasitic nematodes. Determining the PR gene expression and the resistance reaction of Phaseolus vulgaris L. genotypes against root-knot nematode are valuable for understanding plant–nematode interactions. However, resistance reactions of P. vulgaris genotypes and the gene expression of host–nematode interactions are not fully understood. Therefore, this study aimed to determine the expression of PR genes during the infection of Meloidogyne incognita on resistant and susceptible bean varieties at 1, 3, 5, and 7 days postinfection (dpi). The results revealed that one genotype gave a reaction as “immune”, and numerous genotypes were susceptible. The expression of PvPR1 and PvPR2 genes reached the highest peak at 1 dpi in nematode-infected immune plants, and the expression of PvPR1 reached 5 dpi in susceptible plants. In conclusion, PR genes involved in nematode resistance and parasitism and the immune common bean genotype have great potential in breeding programs and understanding the exact location of resistance on the gene map would be advantageous as future work.

Several pathogens, including nematodes, have severe effects on plant development and growth, and immense populations of parasitic nematodes may cause plant death and crop loss. Obligate plant-parasitic nematodes and root-knot nematodes belonging to the genus Meloidogyne are significant parasites in crops. During nematode infection, damage-associated molecular patterns play a role in the activation of plant defence responses to pathogens. Several genes are involved in Meloidogyne parasitism. However, the expression of nematode-responsive genes CRF1, WRKY45, and PR7 during infection with different parasitic nematode species is not well understood. Therefore, this study aimed to reveal plant responses to differential gene expression of nematode-responsive genes in tomato plants, and their relationship to nematode reproduction and comparative phylogeny. Molecular methods for gene expression, greenhouse work for nematode reproduction, and phylogenetic analysis were used to determine nematode–plant interactions. The results revealed that differential gene expression of CRF1, WRKY45, and PR7 depended on the nematode species. The relative CRF1 gene expression reached its highest level at 3 dpi, following nematode infection. In conclusion, plant defense responses disturbed the expression of nematode-responsive genes, and the differential expression of nematode-responsive genes was affected by nematode species and nematode parasitism.

Strawberry is an important crop for many features, including being rich in vitamins and minerals. In addition to fresh consumption, it has been appealing to a wide range of consumers in recent years. Its cultivation is in flat areas, slopes, and areas where other crops are limited. Many pests and diseases that are the main biotic stress factors cause significant crop losses in strawberry cultivation. The aim of this chapter is to reveal biotic stress factors and their management. Several plant-parasitic nematodes, fungal diseases, weeds, pests, virus diseases, and bacterial diseases are the main biotic stress factors in plant growing and fruit ripening. The preparation of this book chapter is based on previously published sources and researches and manuscripts. In this section, it is aimed to provide readers with new perspectives in terms of collecting data on nematodes, diseases, pests, weeds, and fruit ripening of strawberry plants. The effect and mechanism of those biotic stress factors on strawberry growing are discussed and revealed in this chapter.

Salicylic acid (SA) stimulates the mechanism of the plant defence and involves in a role in plant pathogen interactions. Plant parasitic nematodes are important biotic stresses causing negative effect on plant growth and development. Treatment of plant roots with SA may increase the plant defence mechanisms against biotic stresses. However, the treated effect of SA on plant defence mechanisms against a root-knot nematode, Meloidogyne incognita, has not been fully understood in terms of plant pathogen interactions. Therefore, this study was aimed to determine the most effective SA exposure time on increasing the plant defence and decreasing the nematode parasitism in Solanum lycopersicum. In addition, effects of SA treatment on the expression Pathogenesis Related Gene 5 (PR5) was evaluated. For this aim, tomato seedlings were exposed within 1000µM SA concentration with distinctive time durations. The expression of PR5 gene was accomplished using RT-PCR at 1, 3, 7, 14, 21 days post infection (dpi) for each sample. Root galling index, nematode number and reproduction rate were evaluated. Results revealed that nematode reproduction rate was decreased at in longer durations after SA treatment on roots. The highest nematode reproduction rate was determined in nematode+water (non-SA treatment) application compare to SA treatments. The highest increased level of expression of SlPR5 gene was determined in early (1 dpi) SA treatment + nematode infection. To conclude, SA treatment may increase the plant defence mechanisms and PR5 gene may involve in nematode-plant parasitism.

Salicylic acid (SA) induces the mechanism of the plant defence and plays a role in plant -pathogen interactions. Following the nematode infection, effects of SA treatment on plant weights and the expression of pathogen related gene have not been fully understood. The present study was aimed to determine the effects of SA treatment on the expression Pathogenesis related 1 gene (PR1 gene) and alteration on plant parameters in tomatoes (Solanum lycopersicum). Plant seedlings were dripped within the SA solution. The expression of PR1 gene achieved using RT-PCR at 1, 3, 7, 14, 21-days post infection (dpi) with Meloidogyne incognita. Upregulation of PR1 gene was determined in early (1 dpi) and late (21 dpi). SA treatment and nematode infection altered plant parameters. SA treatment increased the plant defence mechanisms in tomato against Meloidogyne incognita.

Plant hormones, such as auxin, play crucial roles in many plant developmental processes, which is crosstalk with gibberellin and strigolactone. The roles of hormones may vary in the biosynthesis of metabolisms. During the pathogen attack, including plant-parasitic nematodes, viroid, phytoplasma, virus, and bacteria, plant hormones are involved in several plant processes. Ethylene (ET), salicylate (SA), jasmonate (JA), and abscisic acid (ABA) primarily regulate synergistically or antagonistically against pathogens. Those pathogens—nematodes, bacteria, viroid, phytoplasma, and viruses regulate several plant hormones for successful parasitism, influencing the phytohormone structure and modifying plant development. Several genes are related to plant hormones that are involved in pathogens parasitism. In this chapter, how pathogens affect plant hormones in plants growing are discussed.

Potato, Solanum tuberosum, the most important non-grain food crop and essential crop globally, has been widely cultivated around the world for centuries. The significance of this plant is increasing due to high nutritional value of the tubers combined with the simplicity of its propagation. As a plant organ, tuber of potato, is mainly edible part of it and popular as nutrient for almost all nations. Tuberization in potato is a very complex biological occurrence affected by numerous ecological signals, genetics, plant nutrition and several different hormones. Many pests including nematodes limit potato tuber development that plant hormones play roles in nematode feeding cell formation. Parasitic nematodes, important pests which cause damage to plants, tubers, suck up nutrients from plants and weaken plant development and yield losses. Many genes involve in tuber development and plant response nematodes. The aim of this chapter is to demonstrate the new advances in the field of molecular host-nematode interactions and tuber development.

The Mi gene is known to involve in the resistance response to some Root knot nematodes, Meloidogyne spp. in tomato plants Lycopersicon esculentum. Root knot nematodes cause significant damages to almost all crops in the world. Among Meloidogyne species, Meloidogyne incognita is one of the most damages species causing a vast amount of crop loss including tomato plants. The resistance gene may be found in some tomato genotypes or cultivars. Determining the resistance gene, Mi, in tomato cultivars is very important to control root knot nematodes. For this purpose, this study was conducted in 99 tomato genotypes that were screened for resistance against Meloidogyne incognita in molecular and screening assays. Results revealed that Mi gene was only determined in one genotype (Tom113). The result of the screening assay indicated that one of the genotypes (Tom113) showed an immune reaction against the nematode; two genotypes (Tom146, Tom141) were found intermediate; 17 genotypes moderately susceptible, 43 genotypes susceptible and 36 genotypes found highly susceptible. Results of the screening assay confirmed the presence of Mi gene in a tomato genotype, which accompanied with a decreased ability for the nematode in causing the infection. Immune and some promising genotypes are thought as important genetic tools for breeding studies for future works.

Potato (Solanum tuberosum L.) cyst nematodes (Globodera rostochiensis (Wollenweber) and Globodera pallida (Stone) cause significant yield losses and have been listed as quarantine pests for many countries in the world including Turkey, and the European and Mediterranean Plant Protection Organization (EPPO, A2). In Turkey, the current potato production area is decreasing due to contamination by quarantine agents, and new fields are under threat of invasion by new quarantine organisms. In this study, samples were collected from Nevşehir province, Turkey, in potato growing fields during the spring growing season in 2014-2015. Soil samples were washed using Fenwick’s can and cysts were extracted and identified using molecular markers. The species-specific molecular markers generated a 435 bp using PITSr3, PITSp4 and ITS5 primers. The potato golden cyst nematode, G. rostochiensis was identified in Nevşehir potato production areas and this is the first report for the Central Anatolia Region. In addition, G. rostochiensis was found in two samples of the same field in the surveys. The average cyst nematode density was determined as 60 cysts in 250 g soil. Patates (Solanum tuberosum L.) kist nematodları (Globodera rostochiensis (Wollenweber) ve Globodera pallida (Stone) önemli verim kayıplarına neden olmakta, Türkiye de dahil olmak üzere dünyadaki birçok ülke, Avrupa ve Akdeniz Bitki Koruma Örgütü’nde (EPPO, A2) karantina zararlıları olarak listelenmiştir. Türkiye'de mevcut patates üretim alanı karantina zararlısı olarak bulaşmaya bağlı olarak azalmakta ve yeni alanlar yeni karantina organizmaları tarafından istila tehdidi altında bulunmaktadır. Bu çalışmada, Türkiye, Nevşehir ilinden 2014-2015 yıllarında bahar mevsiminde patates yetiştirme alanlarında örnekler toplanmıştır. Toprak örnekleri Fenwick aletinde yıkanarak bulaşık örneklerdeki kistler elde edilmiş ve kist popülasyonlarının moleküler olarak teşhisleri yapılmıştır. Kist popülasyonlarının moleküler düzeyde türe özgü PITSr3, PITSp4 ve ITS5 primerleri kullanılarak yapılan teşhiste söz konusu primerlerin 435 bp de bant oluşturduğu tespit edilmiştir. Bu çalışma sonucunda Nevşehir ili patates ekiliş alanlarında patates kist nematodu G. rostochiensis saptanmış olup, bu sonuç İç Anadolu Bölgesi için ilk kayıt olma özelliğini taşımaktadır. Ayrıca, sürveylerde aynı tarlaya ait iki örnekte G. rostochiensis’e rastlanılmış, 250 g toprakta ortalama 60 kist yoğunluğunda olduğu tespit edilmiştir.

Background The plant parasitic nematode genus Meloidogyne parasitize almost all flowering crops. Plants respond with a variety of morphological and molecular mechanisms to reduce the effects of pathogens. Proteinase inhibitors (PI), a special group of plant proteins which are small proteins, involve in protective role in the plants attacked by microorganisms. Still, the plant response using PI against nematodes has not been well understood. Therefore, this study was aimed to determine the expression of proteinase inhibitor I (PI-I) gene subsequent the infection of M. incognita, M. javanica, and M. chitwoodi in tomato plants post nematode infections. Molecular methods were used to determine the PI gene expressions at different days post nematode infections in host tissues. Results Results revealed that the population of M. incognita species reached the highest level of nematode population followed by M. javanica and M. chitwoodi, respectively. All Meloidogyne species induced expression of PI-I gene reached at the utmost level at 3 days post infection (dpi) in host tissues. Relative gene expression level was sharply dropped at 7 dpi, 14 dpi, and 21 dpi in M. incognita induced gene expression in host tissues. Similar results were observed in host tissues after infection of M. javanica and M. chitwoodi. Conclusions The commonalities of plant response across a diverse Meloidogyne species interaction and the expression of PI gene may be related to plant defense system. Increased level of PI gene expressions in early infection days in host tissues induced by parasitic nematodes may share resemblances to the mechanisms of resistance on biotrophic interactions.

Determining the Optimal Meloidogyne Incognita Inoculum Level, Inoculation Time, Pathogencity and Gall Development on Tomato Roots for Resistance Experiments in Breeding Programs. Root knot nematodes (RKN) cause a significant damage to many cultivated crops and present study was conducted to determine the most appropriate inoculum levels of a ubiquitous RKN nematode in warm climate, Meloidogynev incognita, inoculation time and plant age for the screening of nematode resistance studies on plant breeding programs under controlled conditions. The inoculum level experiment was conducted to investigate the effect of four M. incognita inoculum levels (1000, 1500, 2000, 2500 juveniles/ 1000 gram soil mix) on three different age of susceptible tomato plants. Gall development was observed at 3 different ages susceptible tomato plants with 7 different time points. The highest gall numbers were observed on nematode infected 3 day old plant roots and the least number of galls were detected on the roots of 5 day old plants. First galls were observed at 1 dpi and the highest gall number was observed on the 21st gall counting day on three day old tomato roots. Thus the inoculation of 2000- 2500 second stage juveniles /1000 gram soil mix to 3 days old tomato plants was the best to reach high gall numbers which are suitable for screening of nematode resistance studies on plant breeding programs5