scholarly journals Sporangium-Specific Gene Expression in the Oomycete Phytopathogen Phytophthora infestans

2003 ◽  
Vol 2 (6) ◽  
pp. 1376-1385 ◽  
Author(s):  
Kyoung Su Kim ◽  
Howard S. Judelson

ABSTRACT The oomycete genus Phytophthora includes many of the world's most destructive plant pathogens, which are generally disseminated by asexual sporangia. To identify factors relevant to the biology of these propagules, genes induced in sporangia of the potato late blight pathogen Phytophthora infestans were isolated using cDNA macroarrays. Of ∼1,900 genes known to be expressed in sporangia, 61 were up-regulated >5-fold in sporangia versus hyphae based on the arrays, including 17 that were induced> 100-fold. A subset were also activated by starvation and in a nonsporulating mutant. mRNAs of some genes declined in abundance after germination, while others persisted through the germinated zoospore cyst stage. Functions were predicted for about three-quarters of the genes, including potential regulators (protein kinases and phosphatases, transcription factors, and G-protein subunits), transporters, and metabolic enzymes. Predominant among the last were several dehydrogenases, especially a highly expressed sorbitol dehydrogenase that accounted for 3% of the mRNA. Sorbitol dehydrogenase activity also rose during sporulation and several stress treatments, paralleling the expression of the gene. Another interesting metabolic enzyme resembled creatine kinases, which previously were reported only in animals and trypanosomes. These results provide insight into the transcriptional and cellular processes occurring in sporangia and identify potential targets for crop protection strategies.

2021 ◽  
Author(s):  
Christopher A Brosnan ◽  
Anne Sawyer ◽  
Filipe Fenselau Felippes ◽  
Bernard J Carroll ◽  
Peter M Waterhouse ◽  
...  

Topical application of double-stranded RNA (dsRNA) as RNA interference(RNAi) based biopesticides represents a sustainable alternative to traditional transgenic, breeding-based or chemical crop protection strategies. A key feature of RNAi is its ability to act non-cell autonomously, a process that plays a critical role in plant protection. However, the uptake of dsRNA upon topical application, and its ability to move and act non-cell autonomously remains debated and largely unexplored. Here we show that when applied to a leaf, unprocessed full-length dsRNA enters the vasculature and rapidly moves to multiple distal below ground, vegetative and reproductive tissue types in several model plant and crop hosts. Intact unprocessed dsRNA was detected in the apoplast of leaves, roots and flowers after leaf application and maintained in subsequent new growth. Furthermore, we show mobile dsRNA is functional against root infecting fungal and foliar viral pathogens. Our demonstration of the uptake and maintained movement of intact and functional dsRNA stands to add significant benefit to the emerging field of RNAi-based plant protection.


Food Security ◽  
2021 ◽  
Author(s):  
Jonathan Yuen

AbstractPotato late blight, caused by Phytophthora infestans, is a critical disease of potato and other solanaceous crops, such as tomato. The history of late blight is, in some ways, the history of modern plant pathology. It received much attention in the mid 1800’s by causing the Irish potato famine, and the pathogen played a prominent role in the development of the concept of plant disease and plant pathogens. The pathosystem has also been important in the development of pesticides that are active against plant pathogens, and has also been a model system in understanding concepts ranging from cellular processes, such as how resistance to plant pathogens functions, to large scale processes, such as implementation of regional plant disease warning systems. P.infestans has a secured a place in modern potato production, both in developed and less-developed countries.


2010 ◽  
Vol 23 (5) ◽  
pp. 585-592 ◽  
Author(s):  
Lennart Eschen-Lippold ◽  
Simone Altmann ◽  
Sabine Rosahl

Inducing systemic resistance responses in crop plants is a promising alternative way of disease management. To understand the underlying signaling events leading to induced resistance, functional analyses of plants defective in defined signaling pathway steps are required. We used potato, one of the economically most-important crop plants worldwide, to examine systemic resistance against the devastating late blight pathogen Phytophthora infestans, induced by treatment with dl-β-aminobutyric acid (BABA). Transgenic plants impaired in either the 9-lipoxygenase pathway, which produces defense-related compounds, or the 13-lipoxygenase pathway, which generates jasmonic acid–derived signals, expressed wild-type levels of BABA-induced resistance. Plants incapable of accumulating salicylic acid (SA), on the other hand, failed to mount this type of induced resistance. Consistently, treatment of these plants with the SA analog 2,6-dichloroisonicotinic acid restored BABA-induced resistance. Together, these results demonstrate the indispensability of a functional SA pathway for systemic resistance in potato induced by BABA.


2007 ◽  
Vol 34 (7) ◽  
pp. 589 ◽  
Author(s):  
Tuan Ngoc Le ◽  
Cecilia K. Blomstedt ◽  
Jianbo Kuang ◽  
Jennifer Tenlen ◽  
Donald F. Gaff ◽  
...  

The desiccation tolerant grass Sporobolus stapfianus Gandoger can modulate cellular processes to prevent the imposition of irreversible damage to cellular components by water deficit. The cellular processes conferring this ability are rapidly attenuated by increased water availability. This resurrection plant can quickly restore normal metabolism. Even after loss of more than 95% of its total water content, full rehydration and growth resumption can occur within 24 h. To study the molecular mechanisms of desiccation tolerance in S. stapfianus, a cDNA library constructed from dehydration-stressed leaf tissue, was differentially screened in a manner designed to identify genes with an adaptive role in desiccation tolerance. Further characterisation of four of the genes isolated revealed they are strongly up-regulated by severe dehydration stress and only in desiccation-tolerant tissue, with three of these genes not being expressed at detectable levels in hydrated or dehydrating desiccation-sensitive tissue. The nature of the putative proteins encoded by these genes are suggestive of molecular processes associated with protecting the plant against damage caused by desiccation and include a novel LEA-like protein, and a pore-like protein that may play an important role in peroxisome function during drought stress. A third gene product has similarity to a nuclear-localised protein implicated in chromatin remodelling. In addition, a UDPglucose glucosyltransferase gene has been identified that may play a role in controlling the bioactivity of plant hormones or secondary metabolites during drought stress.


2017 ◽  
Vol 2 (1) ◽  
pp. 90-91
Author(s):  
Virupaksh U. Patil ◽  
G. Vanishree ◽  
Debasis Pattanayak ◽  
Sanjeev Sharma ◽  
Vinay Bhardwaj ◽  
...  

2017 ◽  
Vol 12 (4) ◽  
pp. e1300733 ◽  
Author(s):  
Soriya Rin ◽  
Yuri Mizuno ◽  
Yusuke Shibata ◽  
Mayuka Fushimi ◽  
Shinpei Katou ◽  
...  

2021 ◽  
Author(s):  
Seogchan Kang ◽  
Rhea Lumactud ◽  
Ningxiao Li ◽  
Terrence H Bell ◽  
HyeSeon Kim ◽  
...  

Heavy reliance on synthetic pesticides for crop protection becomes increasingly unsustainable, calling for robust alternative strategies that do not degrade the environment and vital ecosystem services. There exist numerous reports of successful disease control using various microbes in small-scale trials. However, their inconsistent efficacy has hampered large-scale applications. An enhanced understanding of how beneficial microbes interact with plants, other microbes, and the environment and which factors affect their efficacy of disease control is crucial to deploy microbial allies as effective and reliable pesticide alternatives. Diverse metabolites produced by plants and microbes participate in pathogenesis and defense, regulate the growth and development of themselves and neighboring organisms, help maintain cellular homeostasis under varied environmental conditions, and affect the assembly and activity of plant and soil microbiomes. However, research on the metabolites associated with plant growth/health-related processes, except antibiotics, has not received adequate attention. This review highlights several classes of metabolites known or suspected to affect plant health, focusing on those associated with biocontrol and belowground plant-microbe and microbe-microbe interactions. The review also presents how new insights anticipated from systematically exploring the diversity and mechanism of action of bioactive metabolites can be harnessed to develop novel crop protection strategies.


Author(s):  
Angela Ricci ◽  
Silvia Sabbadini ◽  
Laura Miozzi ◽  
Bruno Mezzetti ◽  
Emanuela Noris

Abstract Since the beginning of agriculture, plant virus diseases have been a strong challenge for farming. Following its discovery at the very beginning of the 1990s, the RNA interference (RNAi) mechanism has been widely studied and exploited as an integrative tool to obtain resistance to viruses in several plant species, with high target-sequence specificity. In this chapter, we describe and review the major aspects of host-induced gene silencing (HIGS), as one of the possible plant defence methods, using genetic engineering techniques. In particular, we focus our attention on the use of RNAi-based gene constructs to introduce stable resistance in host plants against viral diseases, by triggering post-transcriptional gene silencing (PTGS). Recently, spray-induced gene silencing (SIGS), consisting of the topical application of small RNA molecules to plants, has been explored as an alternative tool to the stable integration of RNAi-based gene constructs in plants. SIGS has great and innovative potential for crop defence against different plant pathogens and pests and is expected to raise less public and political concern, as it does not alter the genetic structure of the plant.


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