The Effect of Virulence and Resistance Mechanisms on the Interactions between Parasitic Plants and Their Hosts

Abstract

Parasitic plants have a unique heterotrophic lifestyle based on the extraction of water and nutrients from host plants. Some parasitic plant species, particularly those of the family Orobanchaceae, attack crops and cause substantial yield losses. The breeding of resistant crop varieties is an inexpensive way to control parasitic weeds, but often does not provide a long-lasting solution because the parasites rapidly evolve to overcome resistance. Understanding mechanisms underlying naturally occurring parasitic plant resistance is of great interest and could help to develop methods to control parasitic plants. In this review, we describe the virulence mechanisms of parasitic plants and resistance mechanisms in their hosts, focusing on obligate root parasites of the genera Orobanche and Striga. We noticed that the resistance (R) genes in the host genome often encode proteins with nucleotide-binding and leucine-rich repeat domains (NLR proteins), hence we proposed a mechanism by which host plants use NLR proteins to activate downstream resistance gene expression. We speculated how parasitic plants and their hosts co-evolved and discussed what drives the evolution of virulence effectors in parasitic plants by considering concepts from similar studies of plant–microbe interaction. Most previous studies have focused on the host rather than the parasite, so we also provided an updated summary of genomic resources for parasitic plants and parasitic genes for further research to test our hypotheses. Finally, we discussed new approaches such as CRISPR/Cas9-mediated genome editing and RNAi silencing that can provide deeper insight into the intriguing life cycle of parasitic plants and could potentially contribute to the development of novel strategies for controlling parasitic weeds, thereby enhancing crop productivity and food security globally.

Phytohormones Trigger Drought Tolerance in Crop Plants: Outlook and Future Perspectives

“…Based on phytohormone physiological functions and chemical structures, there were only a few regulatory hormones, namely jasmonic acid (JA), salicylic acid (SA), ethylene (ET), auxins (IAA), gibberellins (GAs), abscisic acid (ABA), and cytokinins (CKs), which have been more often studied by plant biologists ( Dubois et al, 2018 ). However, presently, brassinosteroids (BRs), jasmonic acid-based compounds, cytokinins based compounds (zeatin), salicylic acid-based compounds, strigolactones, and peptides are also being investigated as plant hormones ( Hu et al, 2020 ). Based on the chemical structures of some specific groups, phytohormones are further subdivided ( Péret et al, 2013 ) and are responsible for the formation of roots and tropism and elongation.…”

Memperbaiki Serapan Hara dengan Aplikasi Bahan Organik untuk Meningkatkan Resistensi Tanaman Cabai terhadap Virulensi Kutukebul

“…Hasil uji berganda pada Tabel 8 menunjukkan hubungan yang cukup kuat dengan arah positif antara senyawa hara pada jaringan tanaman dengan resistensi tanaman terhadap virulensi kutukebul sebesar 63% dengan probabiliti < 0.05. Menurut Hu et al (2020) interaksi nutrisi dengan serangan patogen tidak dapat dijelaskan secara utuh karena sifatnya yang kompleks dan tergantung pada sejumlah faktor eksternal lain. Toksisitas logam maupun ketidakseimbangan hara akan memengaruhi kerentanan terhadap virulensi yang disebabkan abnormalnya fungsi morfologis dan fisiologis tanaman, terutama yang berkaitan dengan penyerapan nutrisi, asimilasi, translokasi, dan pemanfaatannya (Dordas, 2008;Bala et al, 2018;Belete, 2018)…”

A novel strigolactone receptor antagonist provides insights into the structural inhibition, conditioning, and germination of the crop parasite Striga

“…Aside from resulting in considerable economic loss, parasitic weeds are particularly devastating to subsistence farmers who often use agricultural practices that favour Striga infestations (Hearne, 2009;Tippe et al, 2017a;Fernández-Aparicio et al, 2020). The enormity of the Striga problem in Africa propels research into the genetics of crop host resistance and possible Ag-chemicals solutions to perturb the parasite (Samejima, et al, 2016;Hu et al, 2020). The most pernicious parasitic species, Striga hermonthica (Striga), for example, dies within days of germination in the absence of a host.…”