Thylakoid development and chlorophyll distribution in water-stressed and hormone-treated wheat leaves

1978 ◽  
Vol 56 (16) ◽  
pp. 1941-1945 ◽  
Author(s):  
M. E. Duysen ◽  
T. P. Freeman
Keyword(s):  
Triticum Aestivum ◽  
Abscisic Acid ◽  
Polyethylene Glycol ◽  
Gibberellic Acid ◽  
Protein Complex ◽  
Triticum Aestivum L ◽  
Complex Ii ◽  
Chlorophyll Distribution ◽  
Wheat Leaves ◽  
Pigment Protein Complex

An osmotic stress imposed by polyethylene glycol reduced the number and length of stroma thylakoids, the total thylakoid length, and chlorophyll (Chl) accumulation in pigment–protein complex II during the greening of wheat, Triticum aestivum L. cv. Chris, chloroplasts. The combination treatment of benzyladenine and gibberellic acid applied with the imposed stress increased the number of thylakoids per granum, number and length of stroma thylakoids, total thylakoid length, and accumulation of Chl in pigment–protein complex II but reduced plastid number. Abscisic acid reduced the number and length of stroma thylakoids and the total thylakoid length of developing chloroplasts.

Cytokinins and abscisic acid in hardening winter wheat

1990 ◽  
Vol 68 (7) ◽  
pp. 1597-1601 ◽  
Author(s):  
John S. Taylor ◽  
Munjeet K. Bhalla ◽  
J. Mason Robertson ◽  
Lu J. Piening
Keyword(s):  
Triticum Aestivum ◽  
Abscisic Acid ◽  
Winter Wheat ◽  
Leaf Tissue ◽  
Triticum Aestivum L ◽  
Early Spring ◽  
Growth Chamber ◽  
Late Winter ◽  
Sequence Of Events ◽  
Freeze Dried

During overwintering in a northern climate, winter wheat goes through a hardening process, followed by dehardening in late winter – early spring. This sequence of events may be partially controlled by changes in endogenous hormone levels. Crowns and leaf tissue from field grown winter wheat (Triticum aestivum L. cv. Norstar) seeded at the beginning of September were collected and freeze-dried at monthly intervals during the winters of 1985–1986 and 1986–1987. Material was also sampled and freeze-dried from seedlings grown in a growth chamber under hardening conditions (21 °C for 2 weeks plus 3 °C for 6 weeks) or nonhardening conditions (3 weeks at 21 °C). The tissues were analysed for cytokinins and abscisic acid. Cytokinin levels, measured with the soybean hypocotyl section assay, declined from October onwards and then rose to a peak in late winter (January and February, winter 1986–1987; February and March, winter 1985–1986), subsequently declining again. Abscisic acid, quantitated as the methyl ester by gas chromatography with an electron capture detector, increased in level from October to December, then decreased to a relatively low level between January and March. Hardened seedlings from the growth chamber contained significantly higher abscisic acid levels and significantly lower cytokinin levels than did the nonhardened seedlings. Key words: abscisic acid, cytokinins, hardening, Triticum aestivum, winter wheat.

scholarly journals Association of Bipolaris and Drechslera Species with Bipolaris Leaf Blight (BPLB) Infected Wheat Leaves

2019 ◽  
Vol 43 (1) ◽  
pp. 11-16
Author(s):  
Mst Selina Momtaz ◽  
Shamim Shamsi ◽  
Tapan Kumar Dey
Keyword(s):  
Triticum Aestivum ◽  
Triticum Aestivum L ◽  
Leaf Blight ◽  
Wheat Leaves ◽  
Blight Disease ◽  
Academy Of Sciences

Five species of Bipolaris and two species of Drechslera associated with leaf blight disease of wheat (Triticum aestivum L.) have been described. The associated fungi were Bipolaris cynodontis (Marig.) Shoemaker, B. oryzae (Breda De Haan) Shoemaker, B. sorokiniana (Sacc.) Shoemaker, B. tetramera (Mckinney) Shoemaker, B. victoriae (Meehan & Murphy) Shoemaker, Drechslera dematioidea (Bub. & Wrob.) Subram. & Jain and D. hawaiiensis (Bugnicourt) ex M.B. Ellis; Subram. & Jain. Journal of Bangladesh Academy of Sciences, Vol. 43, No. 1, 11-16, 2019

Relationship of indoleacetic acid and tryptophan to dormancy and preharvest sprouting of wheat

2003 ◽  
Vol 30 (9) ◽  
pp. 939 ◽  
Author(s):  
Shashi Ramaih ◽  
Mohammed Guedira ◽  
Gary M. Paulsen
Keyword(s):  
Triticum Aestivum ◽  
Abscisic Acid ◽  
Inhibitory Action ◽  
Indoleacetic Acid ◽  
Triticum Aestivum L ◽  
Preharvest Sprouting ◽  
Synthetic Auxins ◽  
Relationship Of ◽  
Related Compounds

Preharvest sprouting of wheat (Triticum aestivum L.) involves several plant hormones, but a role for indoleacetic acid (IAA) and its precursor, tryptophan, has not been demonstrated. Our objectives were to determine the roles of IAA, tryptophan, and related compounds in germination of cultivars that differed in susceptibility to preharvest sprouting. L-Tryptophan strongly inhibited germination of embryos excised from caryopses that were highly dormant at harvest but not of embryos from caryopses that had little innate dormancy. The embryos responded similarly to indoleacetaldehyde, IAA, and synthetic auxins, suggesting that tryptophan functioned as a precursor of IAA. Indoleacetaldehyde oxidase inhibitors alleviated the adverse effects of tryptophan and indoleacetaldehyde, and an auxin antagonist decreased the inhibitory action of tryptophan and IAA on embryos from dormant caryopses, further suggesting that IAA was involved. Changes in sensitivity to IAA during afterripening also supported a role for auxin in dormancy. Embryos from caryopses that were highly dormant at harvest gradually lost sensitivity to IAA during afterripening, whereas intact caryopses were insensitive to IAA. The results implicated IAA in dormancy of wheat caryopses and indicated that the auxin might complement the role of abscisic acid in germination. The importance of using dormant caryopses and arresting afterripening in investigations of seed dormancy was noted.

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