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.

Abiotic stresses can cause significant harm to economically important crops, making it essential to adopt sustainable methods to mitigate their negative effects. One promising approach is particle film technology, which has been shown to alleviate the impact of water scarcity and solar radiation on crops. In this study, our goal was to determine the action of particle film used in leaves of Ipomoea batatas L. grown under varying water conditions. Our findings indicate that plants treated with the particle film suffered less harm to their photosynthetic systems, particularly during the reproductive stadium, regardless of the water regime. Furthermore, the exogenous application of the particle film resulted in increased photosynthetic efficiency and electron transport rates in plants, as well as a decrease in the chl a/b ratio and expression of the Cdc2a gene. These results demonstrate that particle film technology has the potential to enhance crop resilience and productivity in sweet potatoes, even in adverse conditions.