Function of boron in plant nutrition

• Boron is a nutrient required for all plant nutrition.
• The main function of boron relate to cell wall strength and development, cell division, fruit and seed development, sugar transport, and hormone development.
• Some functions of boron interrelate with those of nitrogen, phosphorus, potassium and calcium in plants. Balanced nutrition is essential for optimum crop growth.
Boron (B) is required for all plant growth. Adequate B nutrition is critical for high yield and quality of crops. Deficiencies of B result in many anatomical, biochemical and physiological changes in plants.
The most important physiological effects of B in plants now are thought to be a structural role for B in cell walls, a role for B in membrane function, and a stimulator or inhibitor of specific metabolic pathways.
Cell wall structure
Boron is involved along with calcium (Ca) in cell wall structure. Boron is involved in the movement of Ca into the plant and in normal Ca nutrient in plant. There is a similarity between bone developments in animals and cell wall development in plants
Cell division
Boron is essential in the active growing regions of plants, such as root tips, and in new leaf bud development. This involves the meristematic (growing) tissues in plants or the cells which are rapidly multiplexing, allowing plant growth to occur.
A shortage of B is most often noted by a change in plant structure in these actively growing regions. Boron ensures healthy plant storage tissues and conductive tissues for the transport of water, nutrients and organic compounds of the actively growing portions in plants.
Sugar transport
Photosynthesis transforms sunlight energy into plant energy compounds such as sugars. For this process to continue in plants, the sugars must be moved away from the site of their development, and stored or used to make other compounds.
Boron increases the rate of transport of sugars (which are produced by photosynthesis in mature plant leaves) to actively growing regions and also in developing fruits.
Boron is essential for providing sugars which are needed for root growth in all plants and also for normal development of root nodules in legumes such alfalfa, soybeans and peanuts.
Flowering and fruiting
The B requirements are much higher for reproductive growth than for vegetative growth in most plant species. Boron increases flower production and retention, pollen tube elongation and germination, seed and fruit development.
Plant hormone regulation
Plant hormone regulates many growth and reproduction functions. Flower initiation, fruit development, cell wall and tissue formation, and root elongation are all influenced by hormones. Boron plays an important role in regulating hormone levels in plants.