Hey Team,

Thanks for the kind words! I've really enjoyed helping you carry out your project this semester. I was really impressed with your experimental design and interpretation of your results. I also like your ideas about how to apply your findings to agriculture. Great thinking!

Also, thanks for uploading the presentation! It was nice to see more images of what you all did. 

I hope you all enjoy the rest of your school year, and I wish you the best of luck with your futures in science!

Take care,
Ethan

Hi Team!

I like what you've written up in your Project Info section regarding your results (along with everything else!). You did a great job including important details and summing up your findings. 

I'm excited to see your presentation! As the staff pointed out below, we're not able to use Google Drive links here at PlantingScience. You should be able to download or save your presentation as a .pdf and then upload it following the directions below. Can't wait to see it!

Have a great weekend!

Hi Michael,

These are still interesting results, even though your hypothesis was rejected. From your results, it seems that there is likely something other than glucose levels that leads to susceptibility. Here is a website with a little info on soft rot that I found interesting:

https://hort.extension.wisc.edu/articles/bacterial-soft-rot/#:~:text=Soft%20rots%20commonly%20affect%20vegetables,on%20harvested%20crops%20in%20storage.

Here are a couple of quotes from the article:

"Soft rots commonly affect vegetables such as potato, carrot, tomato, cucurbits (e.g., cucumbers, melons, squash, pumpkins), and cruciferous crops (e.g., cabbage, cauliflower, bok choy)."

"Corn, snap beans and beets are vegetables that are not considered susceptible to soft rot."

Did you see any infection on the carrots? I've also read that onions can be susceptible to soft rot, although this article doesn't mention that (and you all didn't see it). 

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There are a lot of potential explanations for your results, but I like your prediction about the vegetable's defense system playing a role! Great thinking!

There are a number of bacteria species that cause soft rot, and certain species of bacteria perform better on different host vegetables. I found a couple of scientific papers that discuss this a bit. They're pretty dense and difficult to read, so I've included highlights from each article.

https://www.frontiersin.org/articles/10.3389/fmicb.2015.01361/full#B90

"Macergens are bacteria capable of releasing pectic enzymes (pectolytic bacteria). These enzymatic actions result in the separation of plant tissues leading to total plant destruction. This can be attributed to soft rot diseases in vegetables. These macergens primarily belong to the genus Erwinia and to a range of opportunistic pathogens namely: the Xanthomonas spp., Pseudomonas spp., Clostridium spp., Cytophaga spp., and Bacillus spp."

• I included this quote because it describes the different genera of bacteria that can cause soft rot.

https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1003013

"...many type III secretion system (T3SS)-dependent plant pathogens, such as Erwinia, Pseudomonas, Xanthomonas and Xylella, have a very narrow host range."

• From this quote, we can see that some plant pathogens are only effective at colonizing certain plant species. Note that three of the bacterial genera listed here as having a narrow host range are mentioned in the above article as macergens that cause soft rot. 

https://www.annualreviews.org/doi/10.1146/annurev.phyto.42.040103.110731

"Many phytopathogenic bacteria inject virulence effector proteins into plant cells via a Hrp type III secretion system (TTSS)."

"The Hrp TTSS employs customized cytoplasmic chaperones, conserved export components in the bacterial envelope (also used by the TTSS of animal pathogens), and a more specialized set of TTSS-secreted proteins to deliver effectors across the plant cell wall and plasma membrane. Many effectors can act as molecular double agents that betray the pathogen to plant defenses in some interactions and suppress host defenses in others."

• This one is especially confusing! But it's basically saying that the mechanism that allows certain bacteria to successfully infect a particular plant species may trigger a different plant species' defenses, preventing infection in those plants. This helps explain why certain bacterial species that cause soft rot are only effective on certain species of plants.

Unfortunately, there's no easy way to identify the species of bacteria that we're working with. One thing to keep in mind is this source of the bacteria we used. Do you think that where we got the bacteria could have an effect? Do you think we may have had different results if the bacteria came from another source? 

I've been very impressed with the ideas this team has come up with! Your experimental design and hypothesis were really well thought out. Even though your hypothesis was rejected, you've come up with a good idea about what could be explaining your results. Keep looking into potential explanations! I'm looking forward to your conclusions!