AgTech Biotech

Precision injection system for plants

Oranges, olives, and bananas are already under threat in many areas due to diseases that affect plants’ circulatory systems and that cannot be treated by applying pesticides. A new method developed by engineers at MIT may offer a starting point for delivering life-saving treatments to plants ravaged by such diseases. The method uses an array of microneedles made of a silk-based biomaterial to deliver nutrients, drugs, or other molecules to specific parts of the plant. The work started in response to a request from the U.S. Department of Agriculture for ideas on how to address the citrus greening crisis, which is threatening the collapse of a $9 billion industry.

The microneedles designed for human use were intended to biodegrade naturally in the body’s moisture, but plants have far less available water, so the material didn’t dissolve and was not useful for delivering the pesticide or other macromolecules into the phloem. The researchers had to design a new material, but they decided to stick with silk as its basis. That’s because of silk’s strength, its inertness in plants (preventing undesirable side effects), and the fact that it degrades into tiny particles that don’t risk clogging the plant’s internal vasculature systems.

The technology has potential to be used to bioengineer disease-resistant varieties of important crops. In experiments with tobacco the researchers were able to inject Agrobacterium to alter the plant’s deoxyribonucleic acid – a typical bioengineering tool, but delivered in a new and precise way.

Read more at MIT News

Food Security

Drug-resistant diseases that jump from plants to humans

The current coronavirus pandemic shows how unprepared humans are in fighting pathogens that originate in wildlife and jump to humans. Human immune systems are equally unprepared for drug-resistant diseases that jump from plants to humans. Drug-resistant fungal diseases are emerging as a major health threat, including Candida auris—a highly infectious fungus. Fungi are continually mutating, and with a very short life cycle measured in days or weeks, they mutate quickly. 

One theory for Candida auris emergence is that the overuse of fungicides killed off all of its competitors, causing C. auris to undergo explosive growth.

The current pandemic offers a clear message that we must be better in mitigating the risks associated with infections. One of the solutions in plants, could be gene editing, that can play a vital role in preventing pathogens from developing the drug resistance. Advances in genetics have given us an understanding of nature’s gene editing process in plants, helping us develop resistance to a disease.

Read more at ScientificAmerican


Don’t guess, test soil temperatures before planting vegetables

It is easy to get excited about planting vegetable seeds and transplants in the vegetable garden, even when it is too early to plant. Planting in soil temperatures that are too cool will lead to poor seed germination and stunted plants that will not produce to their full potential during the growing season. For the sake of simplicity, there are a few vegetable crop groupings that use similar soil temperatures. According to Oregon State University Extension, here are those groupings:

  • 40 Degree Fahrenheit Plant Grouping — These vegetable crops include arugula, fava beans, kale, lettuce, pak choi, parsnips, peas, radicchio, radishes and spinach seed.
  • 50 Degree Fahrenheit Plant Grouping — These vegetable crops include Chinese cabbage, leeks, onions, Swiss chard, and turnips.
  • 60 Degree Fahrenheit Plant Grouping — These vegetable crops include beans, beets, broccoli, Brussels sprouts, cabbage, carrots and cauliflower. Do be careful with planting beans since they are prone to be damaged by a freeze.
  • 70 Degree Fahrenheit Plant Grouping — These vegetable crops include tomatoes, eggplants, peppers, cucumbers, squash, corn and melons. These crops are very prone to damage from a light freeze as transplants, and may take a while to germinate even when the soil is at this temperature threshold.