TY  - EJOU
AU  - Yadav, Kirti A. 
AU  - Jha, Yachana 
AU  - Elkatry, Haiam O. 
AU  - Mohamed, Heba I. 
AU  - Ismail, Ahmed Mahmoud 
AU  - Ahmed, Abdelrahman R. 

TI  - Morpho-Anatomical and Biochemical Defense Responses of Pigeon Pea Varieties to Phytophthora Blight
T2  - Phyton-International Journal of Experimental Botany

PY  - 2026
VL  - 95
IS  - 1
SN  - 1851-5657

AB  - 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.
KW  - Defense-related enzymes; flavonoids; phenolics; protein; soluble sugars

DO  - 10.32604/phyton.2026.074570