Lecture 18: Signaling Pathways

_______ are hormones that occur in plants

phytohormones

most auxin is made in what 3 places?

apical meristem, young leaves, young fruits

What 2 places can auxin be stored in?

ER, vacuole

Auxin is regulated by _____

itself

______ promote cell elongation of internodes, and promotes seed germination, floweing, and fruit development

gibberellins

gibberellin synthesis is regulated by _________

negative feedback

_______ are important for leaf senescence, promotion of sink activity, and development of vascular tissue

cytokinins

cytokinins are made in _______ by using pieces of _____, and are inactivated by ________

plastids, ATP, glycosylation

_______ is important for fruit ripening, senescence and abcission, and seed germination

ethylene

ethylene is made in ____ tissues, is most concentrated in ______ fruits, and because its a _____, there is no _______ of it

all, ripening, gas, breakdown

______ promotes senescence and regulates stomatal closure

ABA

ABA is made in _____ using the same products as the _______, and can be inactivated via _______ with a sugar group, and can also be broken down by being _______

plastids, calvin cycle, conjugation, oxidized

in guard cells, accumulation of _____ triggers ____ to move out of the cell.

Then, because of ______, ____ also goes out of the cell, making the guard cell _____.

ABA, ions, osmosis, water, shrink

________ are important for photomorphogenesis, reproductive development, cell division, elongation, and differantiation

brassinosteroids

brassinosteroids are controlled by a __________

negative feedback loop

_______ are important for surpressing shoot branching, and promoting root hair growth

strigolactones

Which 2 hormones are made from carotenoids, and can diffuse across cell membranes because they’re lipophillic?

ABA, strigolactones

What are 3 ways hormones can move through a plant?

active transport, diffusion of gas, via vascular tissue

_____ and _______ can diffuse across cell membranes bu can also be ________ transported across the membrane

ABA, strigolactones, actively

_______ is a gas, therefore it freely passes through membranes

ethylenes

Which 3 hormones move via vascular tissue?

cytokinins, auxin, ABA

Some hormones can move via vascular tissue due to what 2 things?

transpiration, source-sink

the long-distance movement of auxin via vascular tissue

polar auxin transport

To help auxin move during polar auxin transport, ______ proteins help it move ____ of cells via ____ ______ transport

PIN, out, secondary active

Hormone signalling pathways in animals are primarily _______ regulated, and in plants its primarily ________ regulated

positively, negatively

Because most plant hormone signalling pathways are ______, it means that plants typically _______ proteins that ______ other proteins

negative, inactivate, inhibit

one way to inactivate proteins is to tag them for destruction with a small protein called ______, a process known as ________

ubiquitin, ubiquitination

auxin is self-regulated by a ____ feedback loop in a process called ________

negative, attenuation

Describe the process of auxin regulation itself.

auxin binds to receptor, then auxin repressor proteins are destroyed via ubiquitination, then TFs are no longer inhibited, which synthesize auxin repressor proteins, which makes enzymes that reduce auxin levels

when signalling pathways interact with eachother, its called _________

cross-regulation

Type of cross regulation where 2 input pathways act on the same proteins

primary

type of cross regulation where 2 input pathways regulate separate responses, and one pathway can enhance or inhibit levels of the other

secondary

type of cross regulation where the reponse of 1 input pathway promotes or inhibits the response of another input pathway

tertiary

Which hormone is used to make bigger fruits?

gibberellin

cytokinins are inactivated by _________

glycosylation

Which hormone is located underground?

strigolactones