The Genetic Adaptations for Heat Survival of Arizona Honeysweet in Death Valley

 

The Genetic Adaptations for Heat Survival of Arizona Honeysweet in Death Valley

Benjamin Pruss
BIOL-2110-001 GENETICS
Professor Guy F. Barbato
November 7th, 2025

    Most plants don't survive very well in extreme heat, much less thrive. However, the Arizona honeysweet (Tidestromia oblongifolia) does just that— in Death Valley, no less. All because of a unique cellular ability it has.

    T. oblongifolia can change the shape of the chloroplasts within its cells, the organelles that convert light, water, and carbon dioxide into energy and oxygen. Chloroplasts are usually disc-shaped; however, the Arizona honeysweet plants' chloroplasts can change to a cup shape. Although not certain, scientists believe this shape helps the chloroplasts better trap carbon dioxide. This, combined with other plant responses to heat, such as smaller leaves, allows the plant to thrive in Death Valley's extreme heat. 

    In an experiment conducted by Karine Prado and her associates, Arizona honeysweet growth was measured at 31°C and 47°C, the usual summer temperature in Death Valley. Seeds grown under Death Valley conditions grew significantly larger than those grown at 31°C. This suggests that the plant actually grows better under such harsh conditions. "These plants wait [for] the hottest month just to grow fast," said Prado about the plants. Some scientists believe that this plant's special adaptations could help future crops survive global warming. 

Sources:

https://www.sciencenews.org/article/death-valley-shrub-survival-heat

https://www.sciencedirect.com/science/article/abs/pii/S0960982225013120

Ancient Genetic Program Employed in More Than Just Fins and Limbs: Hox Genes Provide Blueprint For a Diversity of Body Plan Features

 What are Hox genes and how are they important to the developmental process?

             

     Hox Genes are regulatory genes that determine the location and orientation of body parts in animals. These developmental genes vary from animal to animal, and are the reason why flies have two antennae and wings, whereas a fish will form fins. Hox genes do this by being expressed at different locations and times during the development of an embryo. Reversing the pattern in which Hox genes determine the locations of body parts shows a code that forms appendages separate from the body, such as fins or limbs. This information is useful in determining the exact mechanism in which fins developed into limbs over time through the evolutionary process. In addition, scientists are performing experiments to determine how important this code is in the development of specialized structures, as it has already been observed to code for the barbels in paddlefish and the claspers in skates and rays.

     I find this article to be interesting because it explains the importance of Hox genes in the developmental process. It also makes the fundamental concept of why all animals are different from one another clear, as these genes code for the differences between them. This research is also significant because it provides insight into the genetic basis of the evolutionary process.

Source: Ancient Genetic Program Employed in More Than Just Fins and Limbs: Hox Genes Provide Blueprint For a Diversity of Body Plan Features