scholarly journals The effect of seed conditioning, short-term heat shock and salicylic, jasmonic acid or brasinolide on sunflower (Helianthus annuus L.) chilling resistance and polysome formation

2014 ◽  
Vol 36 (10) ◽  
pp. 2547-2554 ◽  
Author(s):  
K. Górnik ◽  
A. Badowiec ◽  
S. Weidner
1999 ◽  
Vol 26 (2) ◽  
pp. 95 ◽  
Author(s):  
Frank Dannel ◽  
Heidrun Pfeffer ◽  
Volker Römheld

Distribution and compartmentation of boron as possible mechanisms for the notable tolerance of sunflower (Helianthus annuus L.) to excess B supply have been studied. Following a short- term treatment (6 h) with 1000 µМ B, the distribution of B between different shoot organs was preferentially directed to the readily transpiring ones. Thus, B distribution in sunflower plants seems to be mainly influenced by transpiration and does not act as a B tolerance mechanism in sunflower. As a second possible mechanism for B tolerance, the compartmentation of B between water insoluble residue (i.e. cell wall) and cell sap (i.e. symplasm) was determined. Additional binding of B in the cell wall in response to excess B supply for 6 h was very low in leaves and negligible in roots. Thus, a substantial contribution of the cell wall in detoxification of excess B can be ruled out. In an additional experiment with a B supply of 1 µМ (marginal) to 1000 µМ (moderately toxic), the compartmentation of B between the apoplasmic fluid and the cell sap was investigated. The B concentration in the apoplasmic fluid was always lower than that in the symplasm. Thus, B was not excluded from the symplasm, but accumulated within it. The apoplasmic fluid did not contribute substantially to the detoxification of excess B in the leaf.


2014 ◽  
Vol 26 (2) ◽  
pp. 109-115
Author(s):  
Krzysztof Górnik

ABSTRACT The aim of the present study was to improve the chilling tolerance of cucumber seedlings. The conditioned seeds in solutions of salicylic or jasmonic acid in concentrations of 10-2, 10-3 or 10-4 M or brassinolide in concentrations of 10-6, 10-8 or 10-10 M were subjected to temperature shock of 0, 2.5, 5, 35, 40 or 45°C for 1, 2 or 4 hours. Seedlings with 3 mm roots were chilled at 0°C for three days. The chilling susceptibility was evaluated by measurements of roots lengths, electrolyte leakage and total dehydrogenase activity. The obtained results indicated that cucumber tolerance to chilling conditions depended on the plant growth regulators used during seed imbibition and its concentration as well as the temperature initiating thermal shock and its duration. The highest tolerance to chilling, expressed by the subsequent growth of roots, was observed after seed conditioning in salicylic acid solutions in a concentration of 10-4 M for 16 h at 25°C, then exposed for 4 h to a shock temperature of 5°C. The length of seedling roots after such treatment was over 12 times longer than the control (imbibed in distilled water and not subjected to short-term temperature impact). An increased chilling tolerance of cucumber seedlings may result from enhanced membrane integrity and total dehydrogenase activity. Further research is needed to explain the mechanism of the positive effects of salicylic acid, jasmonic acid or brassinolide application to reduce the injurious effects of chilling on cucumber seedlings.


Soil Systems ◽  
2021 ◽  
Vol 5 (4) ◽  
pp. 68
Author(s):  
Priya Lal Chandra Paul ◽  
Richard W. Bell ◽  
Edward G. Barrett-Lennard ◽  
Enamul Kabir ◽  
Mohammed Mainuddin ◽  
...  

Sunflower (Helianthus annuus L.), which is widely grown globally for its high-quality edible oil, is reasonably salt and drought tolerant but it is susceptible to waterlogging. In the saline coastal zone of the Ganges delta, sunflower is often exposed to sudden heavy rainfall during early growth but plant tolerance to such events is not known. Hence, we evaluated the effect of short-term soil inundation (referred to as waterlogging) for 0, 24, 48 and 72 h on sunflower at emergence, 2-leaf, and 4-leaf stages in early- and late-sown crops under field conditions (saline, clay-textured soil, and shallow groundwater). Waterlogging for 24 h did not affect sunflower at any stage but waterlogging for 48 and 72 h suppressed emergence and growth at the 2 and 4-leaf stages. Waterlogging for 72 h completely prevented the emergence for early sowing, whereas emergence was less affected for later sowing. Shoot and root dry weight were most affected at the emergence and 2-leaf stage, not at the 4-leaf stage. In conclusion, waterlogging caused by more than 24 h soil inundation at up to the 4-leaf stage severely depressed emergence and growth, indicating the need for effective drainage at sowing of sunflower in the low-lying coastal saline zone of Bangladesh.


2018 ◽  
Vol 53 (3) ◽  
pp. 485-498
Author(s):  
G.P. Kononenko ◽  
◽  
M.I. Ustyuzhanina ◽  
A.A. Burkin ◽  
◽  
...  

2014 ◽  
Vol 2014 (2) ◽  
pp. 83-91
Author(s):  
Alfredo Garcia-Perez ◽  
◽  
Mark Harrison ◽  
Bill Grant ◽  
◽  
...  

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