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Plant Hormone in hindi | Class 11\NEET\AIIMS | Complete Auxin Hormone| With Handwritten notes

More than a century ago an organic substance known as auxin, became the first plant hormone to be discovered.

Auxin is involved in cell enlargement. cells can enlarge in response to changes in turgor pressure and cell walls must be fairly plastic for this expansion to occur. In this auxin plays an important role in softening of cell walls and thus increasing the elasticity of the cell walls of plant which is made up of cellulose.

DISCOVERY OF AUXIN--

Auxin was first discovered and proposed by Charles Darwin and his son Francis Darwin in 1880 in his book ''The Power of moments in plant'' Darwin used canary grass seedlings in their experiments they knew that if light came primarily from One Direction the plant strongly bends towards it and later this activity was confirmed dut to the presence of auxin in plant.

In 1926 F.W went further refined this experiment and supported the observations Went was able to show that a chemical substance enhanced cell elongation and this chemical substance was called ''AUXIN'' which is derived from Greek word ''auxein'' which means to increase.

Experimental works of scientists on Auxin

Features of AUXIN-

it stimulates the cell division.
auxins help in cell elongation by dissolving carbohydrates of the cell wall.
low concentration of AUXIN promote root growth where as high concentration inhibit the root growth but stimulate stem growth.
auxin is responsible for the phenomenon of apical dominance.
Auxin prevents the process of senescence.
Auxin is responsible for phototropism and geotropism.
Auxin is used in Tea Plantation and hedge making due to its property of apical dominance. (the apical Bud of the plant is removed so that the plant cannot increase in its height and it increases laterally or side wise in the plantation, by this technique the woman in the Tea Plantation are able to pluck the tea leaves easily)

tea plantation

Hedge Making

IAA(indole acetic acid) IBA (indole butyric acid) are examples of naturally occurring auxin.

2,4-D dichlorophenoxyacetic acid is a famous herbicide or weedicide and it kills weeds perhaps by stimulating root growth.

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COMPLETE GIBBERLIN HORMONE

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Plant Hormone in hindi |Class 11\NEET\AIIMS | Ncert theory |Complete Auxin Hormone|

In this video I tried to complete the topic auxin of plant hormone in detail and tried to explain each and every concept regarding the phytohormone auxin. Just not included the contribution of scientist as it was not important but, i will soon upload a video exclusively for the contribution of scientist. Video of remaining hormones nd all PYQ (previous year question) will be uploaded soon... guys yrr like,share,subscribe krnaa ......motivation milta h suggestions are most invited ....new videos coming soon