Common weed may be 'super plant' that holds key to drought-resistant crops

There are clues in a common weed about how to create crops that are resistant to the effects of climate change.

In the journal Science Advances, Yale scientists describe how Portulaca oleracea, commonly known as purslane, integrates two distinct pathways to create a novel type of photosynthesis.

According to the senior author of the paper, "This is a very rare combination of traits and has created a kind of'super plant'--one that could be potentially useful in endeavors such as crop Engineering."

Plants have evolved a number of different mechanisms to improve their ability to use sunlight to make food. Corn and sugarcane are examples of plants that can remain productive under high temperatures. Succulents such as cacti and Agaves have another type of photosynthesis called CAM, which helps them survive in deserts and other areas without water. The same biochemical pathway is used by both C4 andCAM to act as add-ons to regular photosynthesis.

The weed purslane is unique in that it is both highly productive and very tolerant of the weather. Scientists believed that C4 and CAM were independent.

The Yale team conducted a spatial analysis of gene expression within the leaves of purslane and found that C4 andCAM activity are completely integrated. The C4 pathway is used to processCAM reactions in the same cells. Unusual levels of protection are provided for a C4 plant.

The model that predicted the emergence of an integrated C4+CAM system was built by the researchers.

The authors say that understanding this novel pathway could lead to new ways to engineer crops such as corn to be able to survive long periods of dry weather.

There is still a lot of work to be done before that could become a reality. The two pathways can be integrated and shared. C4 andCAM are compatible, which leads us to believe that there are many more C4+CAM species out there.

More information: Jose Moreno-Villena et al, Spatial resolution of an integrated C4+CAM photosynthetic metabolism, Science Advances (2022). DOI: 10.1126/sciadv.abn2349. www.science.org/doi/10.1126/sciadv.abn2349 Journal information: Science Advances