Phytophthora blight is a devastating disease of pigeon pea(Cajanus cajan)that severely impacts plant growth and productivity.This study investigates the morphological,anatomical,and biochemical responses of a suscepti...Phytophthora blight is a devastating disease of pigeon pea(Cajanus cajan)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 andβ-1,3-glucanase),compared with the susceptible ICPL 11260.Under P.cajani stress,IPAC-02 maintained significantly elevated osmolyte concentrations(total sugars 153.7 mg g^(−1)FW;proteins 25.4 mg g^(−1)FW),secondary metabolites(phenols 51.7 mg g^(−1)FW;flavonoids 33.1 mg g^(−1)FW),and PR-enzyme activities(chitinase 11.4 U mg^(−1)protein;β-1,3-glucanase 9.1 U mg^(−1)protein).These responses support a lignification-mediated defense mechanism in IPAC-02 and highlight its potential value for breeding Phytophthora-resistant pigeon pea cultivars.展开更多
基金supported and funded by the Deanship of Scientific Research,Vice Presidency for Graduate Studies and Scientific Research,King Faisal University,Saudi Arabia,grant number(KFU252909).
文摘Phytophthora blight is a devastating disease of pigeon pea(Cajanus cajan)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 andβ-1,3-glucanase),compared with the susceptible ICPL 11260.Under P.cajani stress,IPAC-02 maintained significantly elevated osmolyte concentrations(total sugars 153.7 mg g^(−1)FW;proteins 25.4 mg g^(−1)FW),secondary metabolites(phenols 51.7 mg g^(−1)FW;flavonoids 33.1 mg g^(−1)FW),and PR-enzyme activities(chitinase 11.4 U mg^(−1)protein;β-1,3-glucanase 9.1 U mg^(−1)protein).These responses support a lignification-mediated defense mechanism in IPAC-02 and highlight its potential value for breeding Phytophthora-resistant pigeon pea cultivars.
