This article has mentioned some of the toxins, I am not sure whether they have any association with the yellow hallo or not, Article Functional Analysis of the Cytochrome P450 Monooxygenase Gen...

Dear Aqleem,

Thank you for the information. I will read the paper.

Tatyana

Tatyana,

botrydial is requered for HR in plants:

The Sesquiterpene Botrydial Produced by Botrytis cinerea Induces the Hypersensitive Response on Plant Tissues and Its Action Is Modulated by Salicylic Acid and Jasmonic Acid Signaling | Molecular Plant-Microbe Interactions® (apsnet.org)

but, botcinic acid: The Botrytis cinerea phytotoxin botcinic acid requires two polyketide synthases for production and has a redundant role in virulence with botrydial - DALMAIS - 2011 - Molecular Plant Pathology - Wiley Online Library

can be more general toxin targeted on chlroplasts, like toxins of Alternaria spp.

Regards

A.I.

Dear Alex, thank you!

It makes sense in regards to what we see on plants with altered jasmonate level. Another important question is to what extent the movement of these toxins in the leaf tissue outpaces the movement (spreading) of the pathogen itself?

Tatyana

Tanyana,

Toxins are small molecules, the area of their spread should be many folds more than the pathogen occupies. Additionally, plants react differently on Botritis/Sclerotinia toxins.

Zayed, Z. Evaluation of Sclerotinia borealis and S. nivalis as a potential toxin producer / Z. Zayed, E. N. Pakina, A. N. Ignatov // Innovative in Agriculture : сборник статей Х Международной научно-практической конференции, Москва, 28 апреля 2018 года / Москва: Российский университет дружбы народов (РУДН), 2018. – P. 52-56.

Related:

Ultrastructural Changes in Brassica Leaves Caused by Alternaria brassicae and Destruxin B | SpringerLink

Effect of a nonhost‐selective toxin from Alternaria alternata on chloroplast‐electron transfer activity in Eupatorium adenophorum - Chen - 2005 - Plant Pathology - Wiley Online Library

Host-selective toxins produced by the plant pathogenic fungus Alternaria alternata | FEMS Microbiology Reviews | Oxford Academic (oup.com)

Dear, Tanyana,

The fungus Botrytis cinerea produces some phytotoxins, among them the toxin named Botrydial (phytotoxic sesquiterpene metabolite secreted by the fungus Botrytis cinerea which was first isolated and described in 1974).

The phytotoxin Botcinic acid is also produced by Botrytis cinerea. It may causes the lesions on the plant leaves.

You can take a look at the below researches: Botcinic acid biosynthesis in Botrytis cinerea relies on a subtelomeric gene cluster surrounded by relics of transposons and is regulated by the Zn2Cys6 transcription factor BcBoa13.

By: Porquier, A. et al. Curr. Genet. 2019 Aug; 65(4):965-980

Also, you can see: Sesquiterpene synthase from the botrydial biosynthetic gene cluster of the phytopathogen Botrytis cinerea.

By: Pinedo, C. et al. ACS Chem. Biol. 2008 Dec 19;3(12):791-801.

Article Botcinic acid biosynthesis in Botrytis cinerea relies on a s...

Article Sesquiterpene Synthase from the Botrydial Biosynthetic Gene ...

Dear Dr. Salih, Dr. Ignatov,

Thank you for the recommended literature. The symptoms I observe on the infected leaves are quite similar to the situation described for the Alternaria alternata infection: there are two zones, necrotic and chlorotic. According to the literature Botrydial and Botcinic acid are responsible for the necrotic lesion formation, but obviously, other metabolites are responsible for the chlorosis.