Hide this


Plant Science: How Vascular Systems Sustain Life

Plant vascular systems help transport lifeblood throughout the plant. Plant vascular systems help transport lifeblood throughout the plant.


Flowering plants, just like all other living things on earth, possess a vascular system made up of a network of veins that carries important substances throughout the body. A herbaceous plant body may be limited only to a stem, shoots, leaves, and flowers but each must be linked to the other in order to allow for various metabolic process to stimulate growth.

Processes such as photosynthesis, water and nutrient distribution, and food storage all rely on the vascular system of a plant body to move materials to every corner of plant tissue. In animals, the vascular system is a system of blood vessels and capillaries. In plants, the vascular system is made up of two specialized arteries, the xylem and the phloem.

In animals, the vascular system is distributed through muscle mass in a pattern more or less consistent between species. In botany, flowering perennial plants, also called angiosperms, are divided into two evolutionary sub-categories called monocots and dicots. Monocots and dicots have a handful of distinguishing characteristics, the most notable being that monocots have one embryonic leaf after germination and dicots have two.

Inside your growing plant are the microscopic tubes that transport its very own lifeblood throughout.

Monocots have xylem and phloem arteries that are bundled together in pairs and distributed evenly throughout a plant body. Herbaceous dicots have bundled pairs of xylem and phloem too but their vascular tissue is arranged in a ring formation like a tree, with the phloem on the outer ring and xylem facing inwards.

Phloem is photosynthesis's transporter, moving the sucrose and photosynthate generated within photosynthesizing chloroplast to all parts of the plant.  Although the transport of nutrients through phloem has been hypothesized to occur in two ways, the most commonly observed is called active transport.

In this theory, the long tubular pipes of phloem are thought to load and unload sugars from photosynthesizing centers. Inside the phloem are elements called sieve-tubes, which look like hollow tubes perforated with tiny holes at either end. Plant cells in a sugar source will "push" nutrients into the sieve-tube, causing water to enter in simultaneously as a result of osmosis.

This creates a pressure that pushes the nutrients down the tube. When the sugars reach their destination, the cells actively transport the sucrose out of the sieve-tube, releasing pressure and allowing cells at the top continue loading. Phloem also transports amino acids, certain hormones, and messenger RNAs and is thought to be involved in many more plant functions that are still being researched by botanists today. Phloem tissue is alive.

Xylem, on the other hand, does not transport materials both up and down. Xylem moves water and soluble mineral nutrients from the roots of a plant upward. Xylem is also formed by hollow tubes that have slit-like perforations. These vessel elements are made of dead tissue, unlike phloem. Water moves from the roots up through the vessel elements of xylem through transpirational pull and root pressure.

In transpirational pull, as water evaporates from stems and leaves, water that is stored in a root system is pulled upwards in a capillary action by surface tension and negative pressure. Root pressure is much the same, although the pressure involved in this process is positive. Water is moved by osmosis from the soil into a root and subsequently pushed up the xylem from below.

Inside your growing plant are the microscopic tubes that transport its very own lifeblood throughout. It's difficult to look at your plants the same way!

© Copyright RosebudMag.com, 2013

To create link towards this article on your website,
copy and paste the text below in your page.

Preview :

Powered by Rosebudmag © 2021
Follow Rosebud Magazine on Twitter Check out the Rosebud Magazine Facebook
Share this article with your friends, family and co-workers
Inform yourself about the science of plant vascular systems with helpful videos like this one.
Last modified on Thursday, 03 October 2013 05:38

Want To Grow Bigger?



Follow growers on Twitter


FacebookButtonJoin grower discussions on Facebook


email-icon-1Ask our expert growers questions at: experts@rosebudmag.com

Growers Underground
© Rosebud Magazine, 2010 - 2018 | All rights reserved.

Login or Register