Maize and Common Bean Seed Exudates Mediate Part of Nonhost Resistance to Phytophthora sojae Prior to Infection

• Published in: Phytopathology Vol. 112; no. 2; pp. 335 - 344
• Main Authors: Zhang, Zhuoqun, Zhao, Yifan, An, Tai, Yu, Han, Bi, Xiangqi, Liu, Haixu, Xu, Ying, Yang, Zhiyue, Chen, Yufei, Wen, Jingzhi
• Format: Journal Article
• Language: English
• Published: United States 01-02-2022
• Subjects: Exudates and Transudates; Glycine max; Phaseolus; Phytophthora - physiology; Plant Diseases; Seeds; Zea mays; Phytophthora sojae; response mechanism; seed exudates; proteomics; nonhost resistance; oomycetes
• ISSN: 0031-949X; 1943-7684
• DOI: 10.1094/PHYTO-05-21-0213-R

does not infect nonhost maize (
) but infects nonhost common bean (
) under inoculation. Soybean seed exudates participate in mediating host resistance to
.
before infection. This study aims to elucidate the role of seed exudates in mediating the nonhost resistance of maize and common bean to
.
before infection. The behaviors of
.
zoospores in response to the seed exudates were determined using an assay chamber and a concave slide. The proteomes of
.
zoospores in response to the seed exudates were analyzed with the tandem mass tag method. The key proteins were quantitatively verified by parallel reaction monitoring. Maize seed exudates exerted a repellent effect on zoospores of
.
. This result explains why zoospores sense repelling signaling molecules in maize seed exudates that weaken and strongly inhibit chemotaxis signals in the phosphatidylinositol signaling pathway and arachidonic acid metabolism pathway. Common bean seed exudates did not exhibit any attraction to the zoospores because the guanine nucleotide-binding protein signaling pathway, which is responsible for transmitting chemotactic signals, had no significant change. The proteins protecting the cell membrane structure were significantly downregulated, and the early apoptosis signal glutathione was enhanced in zoospores responding to common bean seed exudates, which resulted in dissolution of the cysts. Maize and common bean seed exudates mediate part of the nonhost resistance to
.
via different mechanisms before infection. The immunity of maize to
.
is caused by the repellent effect of maize seed exudates on zoospores. Common bean seed exudates participate in mediating nonhost resistance by dissolving the cysts.