The Visitor

Amber Hafeez

I fall upon your flag leaf,
germ tubes latching, latticing,
slithering past your guard cells,
creeping along corridors, around corners,
masked amid the apoplast,
my mycelia multiplying, matting,
marauding through your mesophyll,
cramming between cracks in the walls,
deploying proteins to distract and disarm.

I am espoused to shadows, recesses;
you scry for my old guise,
that eternal nemesis needling you
since civilisation began;
your limbs were longer, your ears lighter, 
but I’ve evolved with you,
gaining ground with each generation,
shuffling chromosomes with my kin.
My hyphae cobweb your walls
because we are talking in different tongues -
I am too strange to conjugate,
you have allowed me to settle in.

Your cells shrink as I indulge in the finale;
walls crack and crash around you,
blight unravelling in blanched lesions
as I ravage the scraps to birth spores
that swell through your sacked stomata.
My children will corrupt your countless siblings,
crowded around you, choking on air
dead with stringencies - 
a mass rigor mortis of monoculture.
If only you had recognised me.

The Science

Septoria tritici blotch is a devastating foliar disease of wheat caused by the fungal pathogen Zymoseptoria tritici. It enters leaves through pores called stomata. For up to three weeks, the fungus spreads asymptomatically, secreting proteins that suppress host defences. There is then a switch to necrotrophy where the pathogen destroys host tissue and uses these nutrients to produce fruiting bodies that secrete spores through the stomata, allowing the infection to spread. 

Septoria and wheat have been coevolving in an eternal ‘arms race’ since wheat was domesticated 10,000 years ago. Breeders try to improve disease resistance so that wheat can recognise and stop the disease, whilst Septoria evades recognition by changing the proteins it secretes.

The Poet

I am currently a PhD researcher at the John Innes Centre, Norwich, investigating sources of genetic disease resistance to Septoria tritici blotch in wild relatives and landraces of wheat, which contain much untapped genetic variation. I have always enjoyed writing, especially when it allows me to communicate my science more effectively. I was born in Dublin, did most of my growing up in Sutton, South London, then went on to complete an undergraduate degree in Biology at the University of Southampton. I live in Norwich with my two pet degus, surrounded by far too many plants and books!

Next poem: Under a Cloud by Martin Zarrop