Entertainment · August 6, 2022

Purslane is a “SUPERPLANT” that holds the key to drought-resistant crops, scientists claim

Not such a pest! Common garden weed Purslane is a “SUPERPLANT” that holds the key to drought-tolerant plants, scientists claim

  • Purslane is a common weed that many people struggle with in their gardens
  • The plant is able to survive drought while remaining highly productive
  • In a new study, researchers found that the plant integrates two distinct metabolic pathways to create a novel mode of photosynthesis

Purslane can be an avid gardener’s nightmare, but a new study might make you think twice about getting rid of the weed.

Yale researchers claim purslane could be a “superplant” that holds the key to drought-resistant crops.

In their study, the researchers found that the plant integrates two distinct metabolic pathways to create a novel type of photosynthesis.

This allows the grass to survive drought while remaining highly productive.

‘This is a very rare combination of traits and has created a kind of ‘superplant’ – a plant that could potentially be useful in endeavors such as plant breeding,’ said Professor Erika Edwards, lead author of the study.

Purslane can be an avid gardener’s nightmare, but a new study might make you think twice about getting rid of the weed

What is purslane?

Purslane, Portulaca oleracea, is an edible, leafy, frost-sensitive plant commonly used as a herb and salad vegetable.

The fleshy reddish stems are densely covered with lobed leaves that are either green or gold depending on the variety and grow to 15-20 cm in height.

Purslane grows quickly from seed and the leaves are ready for picking in 6-8 weeks.

Source: Gardeners World

Photosynthesis is the process by which green plants use sunlight to synthesize nutrients from carbon dioxide and water.

Over time, different species have independently evolved a number of different mechanisms to enhance this process.

For example, corn and sugarcane have evolved “C4 photosynthesis,” which allows them to remain productive even at high temperatures.

Meanwhile, cacti and agaves have evolved “CAM photosynthesis” that allows them to thrive in areas with little water.

While C4 and CAM serve different functions, they both use the same biochemical pathway to act as “add-ons” to basic photosynthesis.

Previous studies have shown that purslane possesses both the C4 and CAM adaptations, allowing the plant to be productive and tolerant during droughts.

So far, however, it has been assumed that C4 and CAM work independently within the sheets.

In their new study, the researchers showed that C4 and CAM activity are fully integrated in purslane.

In their study, the researchers found that the plant integrates two distinct metabolic pathways to create a novel type of photosynthesis.  This allows the grass to survive drought while remaining highly productive

In their study, the researchers found that the plant integrates two distinct metabolic pathways to create a novel type of photosynthesis. This allows the grass to survive drought while remaining highly productive

Researchers studied gene expression in purslane leaves and found that C4 and CAM both act in the same cells, with products from the CAM responses being processed directly into the C4 pathway.

Researchers hope the findings can help pave the way for drought-resistant crops in the future.

‘In terms of developing a CAM cycle in a C4 crop like maize, there is still a lot to do before this could become a reality,’ explained Professor Edwards.

“But what we have shown is that the two paths can be efficiently integrated and share products.

“C4 and CAM are more compatible than we thought, leading us to suspect there are many more C4 + CAM species out there waiting to be discovered.”

The study comes as parts of the UK are experiencing the driest conditions since the 1976 drought.

Worryingly, the Met Office has warned of “very little significant rain” on the horizon – with conditions now so extreme that a hose ban comes into effect at 5pm today, affecting a million people across Hampshire and the Isle of Wight are affected.

The Met Office says it’s too early to know how long the heatwave will last.

However, it affirms that “there are signs of a return to more unsettled conditions from around mid-August”.

HOW DOES PHOTOSYNTHESIS WORK?

Photosynthesis is a chemical process used by plants to convert light energy and carbon dioxide into glucose for the plant to grow, releasing oxygen in the process.

The leaves of green plants contain hundreds of pigment molecules (chlorophyll and others) that absorb light at specific wavelengths.

When light of the right wavelength strikes one of these molecules, the molecule enters an excited state—and energy from that excited state is transported down a chain of pigment molecules until it reaches a specific type of chlorophyll in the photosynthetic reaction center.

Here energy is used to power the process of charge separation required for photosynthesis to proceed.

The “electron hole” left in the chlorophyll molecule is used to “crack” water into oxygen.

Hydrogen ions formed during the water splitting process are eventually used to convert carbon dioxide into glucose energy that the plant used to grow.

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