Sulfur-Induced Resistance against <i>Pseudomonas syringae</i> pv. <i>actinidiae</i> via Triggering Salicylic Acid Signaling Pathway in Kiwifruit

Sulfur has been previously reported to modulate plant growth and exhibit significant anti-microbial activities. However, the mechanism underlying its diverse effects on plant pathogens has not been elucidated completely. The present study conducted the two-year field experiment of sulfur application...

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Bibliographic Details
Main Authors: Zhuzhu Zhang, Youhua Long, Xianhui Yin, Sen Yang
Format: Article
Language:English
Published: MDPI AG 2021-11-01
Series:International Journal of Molecular Sciences
Subjects:
Online Access:https://www.mdpi.com/1422-0067/22/23/12710
Description
Summary:Sulfur has been previously reported to modulate plant growth and exhibit significant anti-microbial activities. However, the mechanism underlying its diverse effects on plant pathogens has not been elucidated completely. The present study conducted the two-year field experiment of sulfur application to control kiwifruit canker from 2017 to 2018. For the first time, our study uncovered activation of plant disease resistance by salicylic acid after sulfur application in kiwifruit. The results indicated that when the sulfur concentration was 1.5–2.0 kg m<sup>−</sup><sup>3</sup>, the induced effect of kiwifruit canker reached more than 70%. Meanwhile, a salicylic acid high lever was accompanied by the decline of jasmonic acid. Further analysis revealed the high expression of the defense gene, especially <i>AcPR-1</i>, which is a marker of the salicylic acid signaling pathway. Additionally, <i>AcICS1,</i> another critical gene of salicylic acid synthesis, was also highly expressed. All contributed to the synthesis of increasing salicylic acid content in kiwifruit leaves. Moreover, the first key lignin biosynthetic <i>AcPAL</i> gene was marked up-regulated. Thereafter, accumulation of lignin content in the kiwifruit stem and the higher deposition of lignin were visible in histochemical analysis. Moreover, the activity of the endochitinase activity of kiwifruit leaves increased significantly. We suggest that the sulfur-induced resistance against <i>Pseudomonas syringae</i> pv. <i>actinidiae</i> via salicylic activates systemic acquired resistance to enhance plant immune response in kiwifruit.
ISSN:1661-6596
1422-0067