Phosphoproteomics Profiling of Cotton (Gossypium hirsutum L.) Roots in Response to Verticillium dahliae Inoculation

Verticillium
wilt is a plant vascular disease causing severe yield
and quality losses in many crops and is caused by the soil-borne plant
pathogenic fungus Verticillium dahliae. To investigate the molecular mechanisms of the cotton–V. dahliae interaction, a time-course phosphoproteomic
analysis of roots of susceptible and resistant cotton lines in response
to V. dahliae was performed. In total,
1716 unique phosphoproteins were identified in the susceptible (S)
and resistant (R) cotton lines. Of these, 359 phosphoproteins were
significantly different in R1 (1 day after V. dahliae inoculation) vs R0 (mock) group and 287 phosphoproteins in R2 (3
days after V. dahliae inoculation)
vs R0 group. Moreover, 263 proteins of V. dahliae-regulated phosphoproteins were significantly changed in S1 (1 day
after V. dahliae inoculation) vs S0
(mock) group and 197 proteins in S2 (3 days after V.
dahliae inoculation) vs S0 group. Thirty phosphoproteins
were significantly changed and common to the resistant and susceptible
cotton lines following inoculation with V. dahliae. Specifically, 92 phosphoproteins were shared in both in R1 vs R0
and R2 vs R0 but not in susceptible cotton lines. There were 38 common
phosphoproteins shared in both S1 vs S0 and S2 vs S0 but not in resistant
cotton lines. GO terms and Kyoto Encyclopedia of Genes and Genomes
pathway analyses displayed an abundance of known and novel phosphoproteins
related to plant–pathogen interactions, signal transduction,
and metabolic processes, which were correlated with resistance against
fungal infection. These data provide new perspectives and inspiration
for understanding molecular defense mechanisms of cotton roots against V. dahliae infection.