Abstract
Abstract
The root-knot nematode
Meloidogyne incognita
secretes specific effectors to manipulate root cells and induce their redifferentiation into multinucleate feeding ‘giant cells’, which are essential for its development. A dedicated screen identified the
Meloidogyne incognita
MiEFF186a effector as a regulator of alternative splicing, a crucial mechanism of transcriptional gene regulation whereby a single gene can produce multiple mature mRNA variants, in plants. EFF186 is expressed in the esophageal glands of nematode juveniles, and
in planta
, it localizes to the nucleus and accumulates in the nucleolus. A yeast two-hybrid approach identified the nucleolar G-patch protein GDP1/CIS2 as a MiEFF186a target in tomato and Arabidopsis. Transcriptomic analyses of
Arabidopsis
roots ectopically expressing
MiEFF186a
or impaired in GDP1/CIS2 function revealed changes in both gene expression and alternative splicing, with partially overlapping responses. Finally, alteration of
GDP1/CIS2
expression by virus-induced gene silencing in
Solanaceae
or in
Arabidopsis gdp1
mutants affects susceptibility to
M. incognita
. Together, these results identify GDP1/CIS2 as a host target of MiEFF186a and support a role for these proteins in the modulation of host RNA metabolism during nematode parasitism.