#Question id: 12718
#Unit 6. System Physiology – Plant
| 
                                                      COLUMN I 
  | 
  
   
                               COLUMN II  | 
 
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 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. 
  | 
 
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 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. 
  | 
 
#Question id: 12719
#Unit 6. System Physiology – Plant
#Question id: 12720
#Unit 6. System Physiology – Plant
#Question id: 12721
#Unit 6. System Physiology – Plant
There are the five groups of late embryogenesis abundant (LEA) proteins found in plants
| 
    Group
  (family name)  | 
  
                              Functional information  | 
 
| 
   I) Group 1    (D-19 family)  | 
  
   a) It is an
  abundant protein in cotton embryos, Each putative dimer of this group may
  bind as many as ten inorganic phosphates and their counterions  | 
 
| 
   II) Group 2     (D-11 family)  | 
  
   b) Possibly functions in ion
  sequestration to protect cytosolic metabolism When LE25 is expressed in
  yeast, it confers salt and freezing tolerance  | 
 
| 
   III) Group 3      (D-7 family)  | 
  
   c) In tomato, a
  gene encoding a similar protein is expressed in response to nematode feeding  | 
 
| 
   IV) Group 4     (D-95 family)  | 
  
   d) Contains more
  water of hydration than typical globular proteins Overexpression confers
  water deficit tolerance on yeast cells  | 
 
| 
   V) Group 5      (D-113 family)  | 
  
   e) Often
  localized to the cytoplasm or nucleus More acidic members of the family are
  associated with the plasma membrane May act to stabilize macromolecules at
  low water potential  | 
 
#Question id: 12722
#Unit 6. System Physiology – Plant
#Question id: 12723
#Unit 6. System Physiology – Plant
