Ca++ particle films on sweet potato plants: Repression of the cdc2a gene and alterations in leaf anatomy under photo-protection

Abstract

Abstract Water restriction combined with strong sunlight can affect the growth and development of crops. Activation of potential stress-associated genes and specific changes in leaf structure can be critical adaptive responses in controlling unfavorable climatic conditions. This work evaluated the expression of the cdc2a gene and leaf anatomical alterations in sweet potato plants photo-protected with Calcium particle film with and without water restriction. Assessments were performed at 12:00, focusing on gas exchange, temperature (air-leaf), Falker index, chlorophyll a fluorescence, gene expression (cdc2a), and leaf anatomy. The protection of plants regarding gas exchange contributed to the potential increase in photosynthetic rate (A) and a more significant difference between air and leaf temperatures (Dif ºC), as positive responses in the adaptive adjustment. There was a reduction in the fluorescence of chlorophyll a, related to the maximum cross-section ABS/CSm, TR0/CSm, RE0/CSm, ET0/CSm, DI0/CSm, and a significant increase in the effective quantum yield (ɸPSII), transport rate (ETR), maximum quantum yield (Fv/Fm), and photochemical quenching (qP). There was the repression of the cdc2a gene, allied to the physiological responses associated with light-intensity stress. Anatomical changes related to climate adaptation occurred for the treatments; and photoprotection with CaO minimized the deleterious effects during the development of sweet potato plants, mainly in the developmental stage of roots.