@Article{phyton.2026.074570,
AUTHOR = {Kirti A. Yadav, Yachana Jha, Haiam O. Elkatry, Heba I. Mohamed, Ahmed Mahmoud Ismail, Abdelrahman R. Ahmed},
TITLE = {Morpho-Anatomical and Biochemical Defense Responses of Pigeon Pea Varieties to Phytophthora Blight},
JOURNAL = {Phyton-International Journal of Experimental Botany},
VOLUME = {95},
YEAR = {2026},
NUMBER = {1},
PAGES = {--},
URL = {http://www.techscience.com/phyton/v95n1/65805},
ISSN = {1851-5657},
ABSTRACT = {Phytophthora blight is a devastating disease of pigeon pea (<i>Cajanus cajan</i>) that severely impacts plant growth and productivity. This study investigates the morphological, anatomical, and biochemical responses of a susceptible variety (ICPL 11260) and a resistant variety (IPAC-02) following infection by Phytophthora. Morphological analyses showed that infection caused a drastic reduction in root length, shoot length, leaf number, fresh weight, and dry weight in the susceptible ICPL 11260 variety, with reductions ranging from 0.5- to 2-fold compared to non-infected controls. Anatomical observations revealed pronounced cellular damage and mycelial invasion in infected ICPL 11260 plants by 30 days after infection, whereas infected IPAC-02 plants exhibited no fungal colonization. Biochemical analyses further demonstrated that the resistant IPAC-02 variety accumulated higher levels of total soluble sugars, proteins, phenols, and flavonoids, along with increased activities of defense-related enzymes (chitinase and β-1,3-glucanase), compared with the susceptible ICPL 11260. Under <i>P. cajani</i> stress, IPAC-02 maintained significantly elevated osmolyte concentrations (total sugars 153.7 mg g<sup>−1</sup> FW; proteins 25.4 mg g<sup>−1</sup> FW), secondary metabolites (phenols 51.7 mg g<sup>−1</sup> FW; flavonoids 33.1 mg g<sup>−1</sup> FW), and PR-enzyme activities (chitinase 11.4 U mg<sup>−1</sup> protein; β-1,3-glucanase 9.1 U mg<sup>−1</sup> protein). These responses support a lignification-mediated defense mechanism in IPAC-02 and highlight its potential value for breeding Phytophthora-resistant pigeon pea cultivars.},
DOI = {10.32604/phyton.2026.074570}
}