Plants (Jan 2023)

Variety-Specific Flowering of Sugarcane Induced by the Smut Fungus <i>Sporisorium scitamineum</i>

  • Liang Shuai,
  • Hairong Huang,
  • Lingyan Liao,
  • Zhenhua Duan,
  • Xiaoqiu Zhang,
  • Zeping Wang,
  • Jingchao Lei,
  • Weihua Huang,
  • Xiaohang Chen,
  • Dongmei Huang,
  • Qiufang Li,
  • Xiupeng Song,
  • Meixin Yan

DOI
https://doi.org/10.3390/plants12020316
Journal volume & issue
Vol. 12, no. 2
p. 316

Abstract

Read online

Sugarcane smut is the most severe sugarcane disease in China. The typical symptom is the emerging of a long, black whip from the top of the plant cane. However, in 2018, for the first time we observed the floral structures of sugarcane infected by smut fungus in the planting fields of China. Such smut-associated inflorescence in sugarcane was generally curved and short, with small black whips emerging from glumes of a single floret on the cane stalk. Compatible haploid strains, named Ssf1-7 (MAT-1) and Ssf1-8 (MAT-2), isolated from teliospores that formed black whips in inflorescence of sugarcane were selected for sexual mating assay, ITS DNA sequencing analysis and pathogenicity assessment. The isolates Ssf1-7 and Ssf1-8 showed stronger sexual mating capability than the reported Sporisorium scitamineum strains Ss17 and Ss18. The ITS DNA sequence of the isolates Ssf1-7 and Ssf1-8 reached 100% similarity to the isolates of S. scitamineum strains available in GenBank. Inoculating Ssf1-7 + Ssf1-8 to six sugarcane varieties, i.e., GT42, GT44, GT49, GT55, LC05-136 and ROC22, resulted in different smut morphological modifications. The symptoms of floral structure only occurred in LC05-136, indicating that the flowering induction by S. scitamineum is variety-specific. Furthermore, six selected flowering-related genes were found to be differentially expressed in infected Ssf1-7 + Ssf1-8 LC05-13 plantlets compared to uninfected ones. It is concluded that the flowering induction by S. scitamineum depends on specific fungal race and sugarcane variety, suggesting a specific pathogen–host interaction and expression of some flowering-related genes.

Keywords