Al3+ Significantly Delayedthe Loss of Chlorophyll (Chl), Protein and Carotenoids When Compared to Ca2+During Dark-Induced Senescence of Detached Primary Leaves of Rice (Oryza Sativa). Thylakoid Membranes Isolated from Al3+ Treated Leavesshowed a Better Retention of Photosystem (Ps Ii), Photosystem (Ps I) and Wholechain Electron (Wce) Transport Activities Than Thyalokoid of Ca2+ Treatedleaves.