Proteomic changes and molecular effects associated with Cr(III) and Cr(VI) treatments on germinating kiwifruit pollen

The present study is aimed at identifying molecular changes elicited by Cr(III) and Cr(VI) on germinating kiwifruit pollen. To address this question, comparative proteomic and DNA laddering analyses were performed. While no genotoxic effect was detected, a number of proteins whose accumulation levels were altered by treatments were identified. In particular, the upregulation of some proteins involved in the scavenging response, cell redox homeostasis and lipid synthesis could be interpreted as an oxidative stress response induced by Cr treatment. The strong reduction of two proteins involved in mitochondrial oxidative phosphorylation and a decline in ATP levels were also observed. The decrease of pollen energy availability could be one of the causes of the severe inhibition of the pollen germination observed upon exposure to both Cr(III) and Cr(VI). Finally, proteomic and biochemical data indicate proteasome impairment: the consequential accumulation of misfolded/damaged proteins could be an important molecular mechanism of Cr(III) toxicity in pollen

New Insights into an Old Story - Pollen ROS also Play a Role in Hay Fever

Reactive oxygen species (ROS) can exhibit negative and benign traits. In plants, ROS levels increase markedly during periods of environmental stress, and defence against pathogen attack. ROS form naturally as a by-product of normal oxygen metabolism, and evenly play an essential role in cell growth. The short ROS lifespan makes them ideal molecules to act in cell signalling, a role they share in both plants and animals. A particular plant organism, the pollen grain, may closely interact with human mucosa and an allergic inflammatory response often results. Pollen grain ROS represent a first, crucial signal which primes and magnifies a cascade of events in the allergic response

POLLEN VIABILITY, GERMINATION AND TUBE GROWTH: A POWERFUL TOOL TO BIOMONITOR AND ASSESS TRACE ELEMENT CYTOTOXICITY

ABSTRACT Pollen is an extremely simplified organism whose crucial task is to produce and convey the male gametes to the egg cell for fertilization. It represents a suitable tool for chemical toxicity investigations. Pollen-based assays represent an easy and sensitive in vitro test of toxicity at the cellular level. We examined the in vitro response of kiwifruit pollen tubes to increasing concentrations of Cr, As, and Pd, assuming tube growth inhibition as an endpoint for determining potential cytotoxicity and expressing the inhibitory effect as a numerical value (EC50). On the other hand, pollen quality can be assumed as a sensitive indicator of heavy metal pollution, which affects pollen developmental processes. We found appreciable differences in pollen quality in vivo, significantly related to major trace metals of the area studied. Thus, pollen represents a potentially good biomonitoring system. It also offers the advantages of large populations, rapid testing, easy storage, and relatively low cost