|MENDU, LAVANYA - Texas Tech University|
|MONCLOVA-SANTANA, CECILIA - Texas A&M Agrilife|
|CHAGOYA, JENNIFER - Texas A&M Agrilife|
|VENUGOPAL, MENDU - Texas Tech University|
Submitted to: Journal of Agriculture and Food Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/15/2022
Publication Date: 11/20/2022
Citation: Mendu, L., Ulloa, M., Payton, P.R., Monclova-Santana, C., Chagoya, J., Venugopal, M. 2022. Lignin and cellulose content differences in roots of different cotton cultivars associated with different levels of Fusarium wilt race 4 (FOV4) resistance-response. Journal of Agriculture and Food Sciences. 10. Article 100420. https://doi.org/10.1016/j.jafr.2022.100420.
Interpretive Summary: Fusarium wilt race 4 or FOV4 is a plant-root fungal disease that results in plant death or significant yield loss in many crops, including cotton. Plants have several mechanisms, both physical and chemical, to prevent FOV4 infection. The most important physical barrier to infection is the cell wall. While plant cell walls are well-studied, their specific role in FOV4 interaction in cotton is unknown. ARS scientists with university cooperators examined root cell wall components of cotton cultivars with varying resistance and susceptibility to FOV4. Biochemical differences in root cell walls were found between susceptible and resistant cultivars. Overall, the present study is the first step in understanding the cell wall-mediated FOV4 resistance and provides an excellent opportunity to develop FOV4 resistance in cotton.
Technical Abstract: Fusarium wilt caused by Fusarium oxysporum f. sp. vasinfectum (FOV) race 4 (FOV4) enters the plant through root system. Plant cell wall forms the primary barrier against pathogen infection in addition to providing the mechanical support. Cell walls are mainly composed of cellulose, hemicellulose, lignin, pectin and matrix proteins and alteration in cell walls confer pathogen resistance in plants. However, the role of cell walls for developing FOV4 resistance has not been explored. The present study focused on examining the variation in lignin and cellulose contents in root tissue of Pima (Gossypium barbadense L.) and Upland (G. hirsutum L.) cotton with different levels of FOV4 wilt resistance-response. Traditional cultivar-checks susceptible Pima S-7 (PS-7), resistant Pima S-6 (PS-6), susceptible Upland Stoneville 474 (STV474), and newly developed Upland resistant PSSJ-FRU14 (U77B) were used in the present study. These four cultivars were evaluated in fields known to be infested with FOV4 and exhibited severe vascular root (VRS) FOV4 wilt symptoms under field conditions. Biochemical differences in root cell walls were investigated first by a rapid visual staining method for lignin (phloroglucinol-HCL) and cellulose (Congo red) of root cross sections at three stages of cotton plant development [cotyledon stage (I), true leaf stage (II) and vegetative stage (III)] and later by estimation of root of lignin and cellulose contents. These studies revealed differences between susceptible and resistant cultivars using the rapid staining methods, which were further confirmed by biochemical methods. This is the first report in lignin and cellulose content of Pima and Upland resistant and susceptible FOV4 cotton cultivars and paves the way for developing cell wall mediated FOV resistance.