Root storage proteins, with particular reference to taproots

2002 ◽  
Vol 80 (4) ◽  
pp. 321-329 ◽  
Author(s):  
J Derek Bewley

The presence of storage proteins has been reported in roots of several perennial and biennial weed and crop species, and particularly in members of the Compositae, Euphorbiaceae, and Leguminosae. In some species the amount of these root proteins fluctuates seasonally, increasing in the fall and winter months and declining in the spring and early summer. Also, the root proteins may decline during regrowth of decapitated plants. The evidence that these proteins play a role as storage proteins is frequently only circumstantial; moreover, they are usually only a relatively minor component of the total nitrogen pool within the root. Only one root protein, that from the dandelion taproot, has been extensively characterized, and it has no properties in common with known vegetative storage proteins. The literature on root proteins is reviewed, with particular emphasis on those present in taproots. The paucity of definitive data allows few conclusions to be reached, and more research is required to establish the role, nature, and importance of root proteins.Key words: taproots, perennial weeds, root proteins, nitrogen pools, storage proteins.

2005 ◽  
Vol 32 (4) ◽  
pp. 335 ◽  
Author(s):  
Kimberly A. Murphy ◽  
Rachel A. Kuhle ◽  
Andreas M. Fischer ◽  
Aldwin M. Anterola ◽  
Howard D. Grimes

Antibodies raised against tonoplast intrinsic proteins (TIPs) were used to probe the functional status of the soybean [Glycine max (L.) Merr.] paraveinal mesophyll (PVM) vacuole during changes in nitrogen metabolism within the leaf. Young plants grown under standard conditions had PVM vacuoles characterised by the presence of γ-TIP, which is indicative of a lytic function. When plants were then subjected to shoot tip removal for a period of 15 d, forcing a sink-limited physiological condition, the γ-TIP marker diminished while the δ-TIP marker became present in the PVM vacuole, indicating the conversion of the PVM vacuole to a storage function. When the shoot tips were allowed to regrow, the γ-TIP marker again became dominant demonstrating the reversion of these PVM vacuoles back to a lytic compartment. The changes in TIP markers correlated with the accumulation of vegetative storage proteins and vegetative lipoxygenases, proteins implicated in nitrogen storage and assimilate partitioning. This research suggests that the PVM vacuole is able to undergo dynamic conversion between lytic and storage functions and further implicates this cell layer in assimilate storage and mobilisation in soybeans.


IAWA Journal ◽  
2003 ◽  
Vol 24 (4) ◽  
pp. 421-428
Author(s):  
Wei-Min Tian ◽  
Zheng-Hai Hu

The distribution pattern of vegetative storage proteins is reported for the first time for 18 species and 2 varieties of twelve genera of Rosaceae. Vegetative storage proteins were present in all the species studied of Prunoideae and absent in Maloideae. Their occurrence in a genus seemed to be either universal or entirely absent. Rosaceae trees were poor in vegetative storage proteins and the form of vegetative storage proteins was not protein body-like. Granular and floccular forms of vegetative storage proteins could be distinguished exclusively in the secondary phloem parenchyma cells and their distribution was cell-specific. Our results suggest that the distribution of vegetative storage proteins in Rosaceae can be considered as a taxonomically diagnostic feature. The nature of the bark proteins with seasonal changes in apple trees is discussed.


2016 ◽  
Vol 25 (10) ◽  
pp. 1110 ◽  
Author(s):  
Dong-Gill Kim ◽  
Habitamu Taddese ◽  
Abrham Belay ◽  
Randy Kolka

We conducted studies to assess the impact of traditional fire management on soil organic carbon and total nitrogen pools. We compared organic carbon and total nitrogen pools in forest floor and mineral soil (0–100-cm depth) in three areas burned by local communities (B) with adjacent unburned areas (UB) (three paired sites; 1, 5 and 9 years since fire; hereafter B1-UB, B5-UB and B9-UB) in a montane forest in southern Ethiopia. Despite differences in time since fire and dominant post-fire vegetation, forest floor and mineral soil organic carbon and total nitrogen concentrations and pools were not significantly different between burned and unburned pairs or across sites. However, mineral soil carbon : nitrogen ratio was significantly higher in the burned area of B9-UB (0–10 cm) and B5-UB (10–20 cm), indicating small losses of nitrogen relative to carbon, likely from plant uptake or possibly leaching of nitrogen post fire. Combined, the data suggest that traditional fire management did not dramatically affect forest floor and mineral soil organic carbon and total nitrogen dynamics at these sites.


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