Physiological Changes Due to Stress of Chromium and Lead in Carthamus tinctorius L.

Abstract

Heavy metal contamination has become a pressing environmental and public health concern, particularly in developing nations. Chromium (Cr) and lead (Pb) are ubiquitous environmental pollutants that pose substantial threats to ecological integrity and human health, even at sublethal concentrations. This study was conducted to elucidate the effects of Cr and Pb stress on photosynthetic pigments and proline content in Carthamus tinctorius L.cv. Zirkon. The findings revealed that Cr and Pb exposure caused a substantial reduction in chlorophyll a, chlorophyll b, total chlorophyll, total carotenoids, and proline content, while simultaneously increasing the Chl a/b ratio in heavy metal-stressed plants. A comparison of Cr and Pb exposure demonstrated that Cr exposure resulted in more pronounced damage compared to Pb exposure at equivalent concentrations. In response to both heavy metal stress, C. tinctorius L.cv. Zirkon plants displayed an increased accumulation of proline. These findings suggest that Cr and Pb exposure profoundly affects chlorophyll and proline content, leading to physiological alterations in C. tinctorius cv. Zirkon.