A boost in plants' plumbing can make them grow faster

Sydney, Feb 15 (ANI): In a new research, Australian scientists have discovered that flowering plants managed to speed up their growth and transform the planet thanks to a boost in their leaf plumbing, a finding that may be useful in developing faster-growing plants.

"The question of how angiosperms (flowering plants) became such a dominant group on Earth has been hotly debated for a long time," said Dr Tim Brodribb, a plant scientist at the University of Tasmania in Hobart.

"Flowers have been very commonly cited as the key to angiosperm success, so our suggestion that leaf evolution is the key to explaining the rise of the angiosperms is significant and controversial," he told ABC Science.

For a plant to grow fast, it must produce food quickly.

During photosynthesis, the plant opens up pore-like structures in its leaves so it can absorb carbon dioxide from the air.

A plant's 'plumbing' system consists of dead hollowed-out cells called xylem, which allow water to be sucked up into the plant from the soil.

And a crucial part of this plumbing is in the leaf, where water must make its way from the xylem, through living tissue.

"If you can look at the density of the veins in a leaf, you can tell its capacity to deliver water," said Brodribb.

"The capacity to transpire water is directly proportional to the capacity to photosynthesise. So it's a proxy for the productivity of the plant," he added.

But, until this study, no one had ever looked at how leaf vein density has changed throughout evolution.

Brodribb and Assistant Professor Taylor Feild of University of Tennessee studied the density of veins in the leaves of over 500 plants, including representatives from the most primitive to the most advanced groups of angiosperms.

They found that shortly after angiosperms evolved, there was a fourfold increase in leaf vein density.

"We demonstrate how this major shift in leaf vein architecture potentially allowed the maximum photosynthetic capacity in angiosperms to rise above competing groups 140 to 100 (million years ago)," said the researchers.

To measure the density of leaf veins, Brodribb and Feild had to pull each leaf apart and measure the total length of its veins.

Brodribb said that the findings could open a whole new world up to plant scientists.

"If we can work out how to increase the density of veins in a plant then we can actually make a plant grow a lot bigger faster," he said. (ANI)