Sinh

Ha Noi national university
Scientific natural university
Faculty of biology
Teacher guide : Professor- Vu Van Vu
Student : Vu Thi Luyen;
Class : K8-honor BA Biology.
Mineral nutrients in plant
Table of contents
Transport membrane:
Basic knowledge and summarize about transport membrane;
Advanced level about transport membrane;
The functions of mineral elements to plants:
Summarize about function of mineral elements to plant;
Deficiency of mineral elements to plants.





Use the image animations to do this problem
Basic knowledge and summarize about transport membrane






Learning about careful ABC-transporter
Advanced level about transport membrane
ABC-transporter architecture
Core domains:
Transmembrane domains (TMDs);
Nucleotide-binding domains (NBDs).
Accessory domains :
Substrate-binding domains in uptake systems (SBPs) ;
Regulatory or catalytic domains.

ABC transporter architecture
ABC transporters may be classified as either half transporters or full transporters

Transmembrane domains
The TMDs are two highly hydrophobic proteins or protein domains


Create the channel through which the substrate passes during translocation



Transmembrane domains
In uptake systems, they form the docking site for the SBP and transduce a signal to the NBDs to bind and hydrolyze ATP
In efflux system, they harbor the substratre binding site(s)
Transmembrane domains
Are bundles of ?-helices that traverse the membrane multiple times in a zigzag fashion
Many typical ABC transporters conform to the paradigmatic "two-times-six" ?- helices structure -12 transmembrane segments (TMSs) per functional unit
Nucleotide-binding domains
The engines of ABC transporters are the NBDs as these power substrate translocation by ATP-binding and hydrolysis.
An NBD consists of two domains, a RecA-like and a helical domain, the latter being specific for ABC transporters.
In the NBD monomer, the ATP-binding site is formed by two conserved sequences, the Walker A (P-loop) and Walker B motifs, present in many ATP-binding proteins and not restricted to ABC proteins (Walker et al., 1982).
Nucleotide-binding domains
These motifs bind the phosphates of ATP and ADP, and coordinate a Mg2+-ion via H2O in the nucleotide-binding site, respectively
A glutamate directly following the Walker B motif might be the catalytic base for hydrolysis, since it binds to the attacking water and Mg2+-ion, and mutation of this residue leads to loss of ATPase activity
The Q-loop also forms hydrogen bonds with Mg2+ and the attacking water
.
Nucleotide-binding domains
In the NBD dimer the signature sequence, LSGGQ, (the motif that distinguishes ABC proteins from other nucleotide-binding proteins) of one NBD binds to the ?-phosphate of ATP bound to the other NBD, thereby completing the nucleotide-binding sites (Davidson and Chen, 2004).
ABC transporter mechanism
The simplest model of SBP-dependent uptake
substrate binds to the SBP
SBP docks onto the TMDs and signals the NBDs to bind ATP
a binding site in the TMDs is made available to the outside, the SBP opens and substrate is transferred to the binding site in the TMDs
ATP hydrolysis dissociates the NBD dimer and change the conformation
ABC Transporters in Plants
An ABC transporter has been found to secrete anti-fungal terpenes across the plasma membrane of tobacco cells.
More commonly, ABC transporters are found at the tonoplast, where they are sometimes referred to as glutathione conjugate pumps, or GS-X pumps, since they often transport molecules that have been covalently attached to glutathione. Glutathione (GS) is a tripeptide (Glu-Cys-Gly) that functions as an important cellular antioxidant molecule .
ABC Transporters in Plants
The vacuolar GS-X pumps of plant cells function in herbicide detoxification, protection against oxidative damage, pigment accumulation, and the storage of antimicrobial compounds .
A family of enzymes called glutathione transferases (GSTs) is responsible for attaching glutathione to the molecule to be transported. The common chemical determinant for GS conjugation is a carbon–carbon double bond adjacent to an electron-withdrawing group (CH2 = CH-Z) (Talalay et al. 1998). Compounds that contain this determinant include the anthocyanins , IAA (indoleacetic acid, or auxin), and various phenolic compounds. Metal-binding polypeptides called phytochelatins, which are synthesized from glutathione, are also transported into plant vacuoles along with their chelated heavy metals via GS-X pumps (Salt and Rauser 1995).
The functions of mineral elements in plants
Macronutrients
Micronutrients
Deficiency of mineral elements to plants
N deficiency symptoms in tomato
P deficiency symptoms in tomato
K deficiency symptoms in tomato
S deficiency symptoms in tomato
S deficiency symptoms
Defective Mg2+ in plants
Corn Mg deficiency symptom
Cotton Mg deficiency symptom
Soybean Mg deficiency symptom
Potato Mg deficiency symptom
Ca deficiency symptoms in tomato
Ca deficiency symptoms
Fe deficiency symptoms in tomato
Fe deficiency in petunia
Cl deficiency symptoms in tomato
B deficiency symptoms in tomato
B deficiency (left) and healthy leaf (right) of canola
Zn deficiency symptoms in tomato
Cu deficiency symptoms in tomato
Cu deficiency symptoms
Mo deficiency symptoms in tomato
Mo deficiency symptoms
Mn deficiency symptoms in tomato.
Mn deficiency symptoms
Thank you very much

Appendix about symptom defective mineral elements in plants.