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General and contact information

Howard Judelson's background
education and interests

The oomycetes
learn more about these exciting organisms

The late blight disease
learn more about the problems that P. infestans causes

Research Interests
Ongoing research projects

Other lab members


Opportunities for graduate study in the lab

Asexual spore biology, page 1 (Introduction)

The asexual spores of P. infestans, called sporangia, play very important roles in the disease cycle. Sporangia serve as the primary inoculum for epidemics caused by P. infestans. Many generations of the asexual cycle occur per season, spreading disease through and between fields. Chemical or environmental conditions that suppress asexual sporulation can control late blight and other diseases by breaking this cycle. Consequently, identifying factors that control sporulation, plus ways to interrupt the normal cell cycle, will lead to new strategies for crop protection.

** life cycle **

Simplified disease cycle of Phytophthora infestans

Sporulation occurs toward the end of the life cycle, forming sporangia on specialized aerial hyphae called sporangiophores. Each sporangium contains multiple nuclei, which can partition into individual zoospores upon germination. Zoospores contain two flagella, which are used to propel the zoospore towards a plant. The zoospores then encyst, send out germ tubes, and penetrate the host.

** sporulation **

hyphae forming aerial sporangiophores.


Asexual sporangia

Questions that we are trying to answer in our studies of sporulation include:

1. What genes and proteins are required for forming sporangia and zoospores?

2. What are the metabolic/cellular/environmental triggers of sporulation?

3. What transcription factors, protein kinases, and other regulators control sporulation?

4. What is the topology of the transcriptional network that controls sporulation?

For some nice SEM pictures of P. infestans spores click here