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Abstract: Gibberellins production by soil fungi received little attention, although substantial work has been carried out on other growth promoting aspects of soil borne fungi. We investigated gibberellins production and growth promoting capacity of a novel fungal strain of Neosartorya, which was isolated from the roots of Chinese cabbage (Bassica rapa L. ssp. pekinensis). Fungal culture filtrates (CF) obtained from pure cultures of 16 endophytic fungi were bioassayed on Waito-C, in order to investigate plant growth promoting capacity of these fungi. The fungal isolate CC-8 induced maximum shoot length of Waito-C (13.0cm) as compared to control treatments. In a separate experiment, the CF of fungus CC-8 significantly promoted plant length and biomass of Chinese cabbage. The fungal CF also increased endogenous bioactive GA1 and GA4 contents of Chinese cabbage. Gibberellin analysis of CF of CC-8 showed presence of both physiologically active and non active gibberellins in higher concentrations (GA1, 1.42ng/ml; GA3, 5.93ng/ml; GA4, 11.36ng/ml; GA7, 3.25ng/ml; GA9, 0.79ng/ml; GA15, 1.18ng/ml). The culture filtrate of CC-8 produced higher amounts of GA3, GA4, GA7 and GA9 than wild type Fusarium fujikuroi, a well known gibberellins producing fungus. The fungal isolate CC-8 was later identified as a new strain of Neosartorya species on the basis of traditional and advance molecular techniques. [Copyright &y& Elsevier]

• Aspergillus fumigatus effectively controls root-knot nematodes in Solanum melongena. • Frequency of root galls dropped by 6.8-fold in A. fumigatus colonized seedlings. • Fungus colonized seedlings had higher levels of SA indicating SA dependent response. • The fungus secreted a number of nematocidal phenols and alkaloids. Because of the endophytic fungi's ability to improve host plant fitness and boost their defense they have been used as to control root knot nematode (RKN) infection. RKNs induce root galls by altering growth pattern in the cell elongation zone, thereby obstructing nutrient transport to various parts of the plant. This project was designed to control RKN infestation in Solanum melongena by utilizing plant-friendly endophytic fungi. Garlic plants were used to isolate endophytic fungi which were then screened for their potential to inhibit RKN in S. melongena. Based on its namatocidal potential, the endophyte strain, named GR was selected and identified to be Aspergillus fumigatus with the help of the internal transcribed spacer (ITS) segment of the rRNA genes. The fungus had the ability to release indole acetic acid (IAA), salicylic acid (SA), phenols and flavonoids. The potential endophytes were assessed for the biocontrol of RKN in S. melongena seedlings grown in pots. The isolated strain conferred resistance to RKN penetration, leading to a substantial reduction in the frequency of root galls by 6.8-fold than the control. In comparison to control, endophyte-associated seedlings exhibited a 50 % increase in SA levels, indicating a SA-dependent defense against RKN. The activity of catalase and ascorbic acid was also boosted to suppress ROS generated in the RKN infested seedlings. The culture of the endophytic isolate contained nematicidal phenol (p-hydroxybenzoic acid, caffeic acid, Calycosin) and an alkaloid (Cyclopenin). These findings suggest that the isolated endophyte confers resistance to RKN in Solanum melongena by modulating host physiology and releasing nematicidal substances. [ABSTRACT FROM AUTHOR]

Abstract: We investigated the effect of prohexadione-calcium (Pro-Ca) on growth characteristics and endogenous gibberellins content of Chinese cabbage grown in the alpine region of South Korea. Pro-Ca was applied at the rates of 200ppm and 400ppm, after 10, 15 and 20 days of transplanting seedlings in to the field. Application of Pro-Ca through foliage improved quality and quantity of yield by promoting Chinese cabbage head yield, number of head leaves, total soluble sugar content and compactness of head. The leaf size was reduced, while the chlorophyll content increased under the influence of elevated Pro-Ca application, when measured after 40 days of transplantation. The endogenous bioactive GA1 and GA4 contents of Chinese cabbage drastically decreased with elevated Pro-Ca, indicating that gibberellins (GAs) biosynthesis was blocked by this chemical. Current study suggests that both of GAs biosynthesis pathways are operational in Chinese cabbage, although non-C13-hydroxylation pathway was found to be the major pathway. GAs were quantified by gas chromatography/mass spectroscopy-selective ion monitoring (GC/MS-SIM). [Copyright &y& Elsevier]

Abstract: The effect of Prohexadione Calcium (Pro-Ca) and daminozide was observed on the growth characteristics and endogenous gibberellin contents of Chrysanthemum morifolium R. cv Monalisa White. Three concentrations viz. 100, 200 and 400ppm of Pro-Ca and a single concentration of daminozide (800ppm) were applied three times with 7 days interval on three weeks old plant under greenhouse condition. Pro-Ca suppressed the plant length up to 30.7% while daminozide inhibited up to 27.12% at optimum concentration. The chlorophyll contents and stem diameter were higher than control, while the fresh weight and flower number insignificantly reduced with such treatments. Gibberellin (GA) analysis showed that Pro-Ca and daminozide application significantly lowered bioactive GA1 content, although the amount of its immediate precursor GA20 was fractionally higher. Bioactive GA4 content was slightly higher than the control while significant difference in GA9 was found between the plants treated with Pro-Ca and daminozide. Current study showed that both early C13 hydroxylation and non-C13 hydroxylation pathways of GA biosynthesis are operational in C. morifolium. [Copyright &y& Elsevier]