TLS Online TPP Program

#Question id: 12718


primary disruptions could be signaling the plant that a change in environmental conditions has occurred and that it’s time to respond by altering existing pathways or by activating stress-response pathways. At least five different types of stress-sensing mechanisms can be distinguished:

                       

                          COLUMN I

 

 

                              COLUMN II

 

A) Physical sensing

 

 

i) usually results from the detection of by-products that accumulate in cells due to the uncoupling of enzymatic or electron transfer reactions, such as the accumulation of ROS during stress caused by too much light.

 

 

B) Biophysical sensing

 

 

ii) often involves the presence of specialized proteins that have evolved to sense a particular stress; for example, calcium channels that can sense changes in temperature and alter Ca2+ homeostasis.

 

 

C) Metabolic sensing

 

 

iii) refers to modifications of DNA or RNA structure that do not alter genetic sequences, such as the changes in chromatin that occur during temperature stress.

 

 

D) Biochemical sensing

 

 

iv) refers to the mechanical effects of stress on the plant or cell structure, for example, the contraction of the plasma membrane from the cell wall during drought stress.

 

 

E) Epigenetic sensing

 

 

v) might involve changes in protein structure or enzymatic activity, such as the inhibition of different enzymes during heat stress.

 

 

  
Match the correct sequence sensing mechanism during in stress;

#Unit 6. System Physiology – Plant
  1. A-iii, B-i, C-iv, D-v, E-ii
  2. A-v, B-iii, C-ii, D-i, E-iv
  3. A-ii, B-iv, C-v, D-iii, E-i
  4. A-iv, B-v, C-i, D-ii, E-iii
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