Coordination and plant hormone

Nastic movements

The movement of a plant part in response at an external stimulus in which the direction of response is not determined by direction of stimulus is called nastic movement.

  • Thigmonastic movement is that non-directional movement of a plant part in response to the touch of an object is called T.M. such as movement of leaves of mimosa pudica plant in response to touch (Non- directional).
  • Photonastic Movement is that non-directional movement of plant in response of light called photonastic movement. Such as opening and closing of petals dandelion flowers in response to intensity of light is an example of N. Movement in which stimulus is light.

Tropism (Tropic movements)

A growth movement of a plant part in response to an external stimulus in which direction of stimulus determines the direction of response is called tropism. It directional movement.

  • Phototropism is the movement of a plant part in response to light. Stem of growing plant bend towards light show +ve while roots shows –ve movement.
  • Geotropism is the movement of plant part in response to gravity. Movement of roots towards it shows +ve while of stem shows-ve geotropism.
  • Movement of plant part in response to a chemical stimulus is called chemotropism. Growth of pollen tube towards ovules during fertilization is +ve movement.
  • Movement of a plant part in response to water is called hydrotropism. Movements of roots always towards water i.e. +ve movement. Other parts which move away from water shows –ve movement.

Movement of plant part in response to touch of an object is called Thigmotropism. Climbing part of plants such as tendrils grow towards any support which they happen to touch & wind around that support.

Plant hormones

Auxin: Naturally occurring auxin is indole 3-acetic acid.

  • It promotes cell enlargement & differentiation.
  • It promotes stem & fruit growth.
  • It induces parthenocarpy (formation of seedless fruits without fertilisation).


effect of gibberellin has been known in Japan where certain rice plants were found to suffer from disease foolish seedling they were sterile. disease was found by Kurosava and Hori. Mevolonic is a precursor for it

  • It stimulates internodes growth in rosette plant just before reproduction.
  • Also induce parthenocarpy.


it is basic in nature that promotes the cell division either alone or in conjugation of Auxin. first isolate by Letham et al in 1964. it is known as Zeatin

  • It promotes cell division in plants.
  • It helps in breaking the dormancy of seed & buds.
  • It delays ageing in leaves.
  • Promote opening of stomata.

Abscisic acid

it is also called as stress hormone because stimulated in adverse condition of environment. it is also called dormin. it was first isolated by Adicott et. al in 1963 in cotton bolls.

  • It promotes dormancy in seeds and buds and inhibits growth.
  • It promotes closing of stomata.
  • excess of its prevent RNA & protein synthesis in leaves.
  • It promotes falling of leaves


it is a gaseous hormone which stimulate transverse growth but retard longitudinal growth. it was first isolated by cracker et al in 1935. its precursor is methionine. it is formed in all part of plant body.

  • Promote ripening of fruits.
  • Promote yellowing of leaves.

142 thoughts on “Coordination and plant hormone”

  1. I have read so many posts on the topic of the blogger lovers but this article
    is genuinely a nice piece of writing, keep it up.

  2. Hey There. I discovered your blog the usage of msn.
    That is a very well written article. I will be sure to bookmark it and
    return to read extra of your helpful information. Thank you for the post.

    I’ll certainly return.

    Check out my web blog Virectin Review

  3. Ӏ’ll immediateⅼ take hold of your rrss feed as Ι can not inn finding yoᥙr e-mail subscription link or e-newsletter
    service. Do you have ɑny? Kіndcly let me reсognize so that I may subscribe.


  4. Hey there! Do you use Twitter? I’d like to follow you if that would be ok.
    I’m definitely enjoying your blog and look forward to new updates.

  5. I always emailed this website post page to all my friends, for the reason that if like to
    read it afterward my contacts will too.

  6. Everything is very open with a very clear description of
    the issues. It was truly informative. Your site is extremely helpful.
    Thanks for sharing!

  7. My husband and i got lucky that Raymond could conclude his
    investigations via the ideas he acquired through your web site.
    It’s not at all simplistic to just be handing out information which men and
    women have been trying to sell. We really figure out
    we need the website owner to be grateful to for this.

    These illustrations you’ve made, the straightforward web site
    menu, the friendships you will make it easier to create
    – it’s got mostly amazing, and it’s making our son in addition to the
    family do think the content is excellent, and that’s seriously vital.
    Many thanks for everything!

    Visit my blog

  8. I wanted to thank you for this fantastic read!!
    I definitely enjoyed every little bit of it. I have you saved as a favorite to look at new stuff you post…

  9. Everyone loves what you guys tend to be up too. Such clever work and reporting!
    Keep up the good works guys I’ve added you guys to my personal blogroll.

  10. Greetings! I know this is kinda off topic but I was wondering which blog platform are you using for
    this site? I’m getting tired of WordPress because I’ve had problems with hackers and I’m looking at options for another
    platform. I would be fantastic if you could point me in the direction of
    a good platform.

  11. hey there and thank you for your information ?
    I?ve definitely picked up anything new from right here. I did however expertise a few technical points using this
    site, since I experienced to reload the site many times previous to I could get it to load correctly.
    I had been wondering if your hosting is OK? Not that I’m complaining, but sluggish loading instances times will sometimes affect your placement in google and can damage your high-quality score if ads and marketing with
    Adwords. Anyway I?m adding this RSS to my email and could look out for a lot more of your respective exciting content.
    Ensure that you update this again soon..

    Look into my site: Glacier Air Conditioner Reviews

  12. Thanks , I have just been searching for information approximately this subject for ages and yours is the greatest I have discovered till now.
    However, what concerning the conclusion? Are you sure about the supply?

  13. Thanks for every other informative web site. The place else may I get that type of info written in such a perfect
    means? I’ve a venture that I’m simply now working on, and I have been at the look
    out for such info.

    My homepage: DFine8

  14. Howdy! Would you mind if I share your blog with my zynga group?

    There’s a lot of folks that I think would really enjoy your content.
    Please let me know. Thank you

  15. Hello There. I discovered your weblog the use of msn. This is an extremely well written article.
    I’ll be sure to bookmark it and come back to read
    extra of your useful information. Thanks for the post.

    I will definitely comeback.

  16. Octal deals premium quality API 5L, ASTM, ASME seamless as well as welded steel pipes with various product carbon and also alloy, stainless, for numerous applications.

  17. Once I initially commented I clicked the -Notify me when new comments are added- checkbox and now every time a comment is added I get 4 emails with the same comment. Is there any way you may take away me from that service? Thanks!

  18. Wow that was strange. I just wrote an extremely long comment but after I clicked submit mycomment didn’t appear. Grrrr… well I’m not writing all that over again. Anyways, just wantedto say excellent blog!

  19. Howdy! This is my first visit to your blog!We are a group of volunteers and starting a new initiative in a community in the same niche.Your blog provided us valuable information to work on. Youhave done a marvellous job!

  20. Superb post however , I was wanting to know if you could writea litte more on this subject? I’d be very thankful if you could elaborate a little bit more.Appreciate it!

  21. Thanks for your personal marvelous posting! I truly enjoyed readingit, you can be a great author.I will always bookmark your blog and may comeback in the future. I want to encourage you to ultimately continue your great posts, have a nice morning!

  22. Wow that was strange. I just wrote an really long comment but after I clicked submit my comment didn’t appear. Grrrr… well I’m not writing all that over again. Regardless, just wanted to say fantastic blog!

  23. Hey! I could have sworn I’ve been to this blog before but after reading throughsome of the post I realized it’s new to me. Anyhow, I’mdefinitely delighted I found it and I’ll be bookmarking and checking backoften!

  24. It’s actually a great and useful piece of information. I am glad that you simply shared this useful info with us. Please stay us up to date like this. Thanks for sharing.

  25. Very nice post. I just stumbled upon your blogand wished to say that I’ve truly enjoyed browsing your blog posts.In any case I’ll be subscribing to your feed and I hope you write again very soon!

  26. I like the helpful information you provide in your articles. I will bookmark your blog and check again here frequently. I am quite certain I’ll learn many new stuff right here! Good luck for the next!

  27. I have to thank you for the efforts you have put in writing this blog.I’m hoping to see the same high-grade content from youlater on as well. In fact, your creative writingabilities has inspired me to get my very own blog now 😉

  28. Howdy! This post couldnít be written any better! Looking at this article reminds me of my previous roommate! He always kept preaching about this. I will send this information to him. Fairly certain he will have a great read. Thanks for sharing!

  29. Greetings! Very helpful advice in this particular article! It is the little changes that make the largest changes. Many thanks for sharing!

  30. Hello There. I discovered your blog using msn. This is a very smartly written article. I will make sure to bookmark it and come back to read extra of your useful info. Thanks for the post. I’ll certainly comeback.

Leave a Comment

Your email address will not be published. Required fields are marked *