Enrichment Of Heavy Metal Cadmium In Non-glandular Trichomes Of Plants And The Remediation Effect On Soil Environment

In recent years,the overall situation of soil heavy metal pollution in China is very severe,and the issue of soil cadmium pollution has been paid more and more attention.With the continuous development of social industrialization,the discharge of industrial wastes and residues,and the excessive use of agricultural chemicals have made soil cadmium pollution problems increasingly serious.At the same time,because Cd is highly toxic,difficult to degrade,and has a long pollution cycle,its bio-enrichment and amplification effects in the ecosystem are also more harmful to the environment and human health.Cd ions are not known to function in any biological organisms.Cd ion is a non-essential element for plant growth and development.Excessive absorption of Cd will reduce the content of chloroplasts in plants,thereby affecting the quality of crops and reducing their yields.It may even transmit Cd to the human body by polluting agricultural products.It has a very bad impact on the physical and mental health of the human body.Plants can absorb and store Cd,and also change the form of Cd and reduce the content of Cd in the body through a series of physiological and biochemical effects.The use of this plant characteristics to repair cadmium pollution has attracted more and more attention from scholars at home and abroad.The accumulation of heavy metals in non-glandular trichome is a detoxification mechanism for plants to cope with heavy metal stress.When caterpillars or aphids crawl on plant leaves,they inevitably touch plant hairs,which are believed to be physically defensive structures.Some insects that crawl on plant leaves not only alter trichome stability but also wound trichomes.Will the insects touching with plant hair affect the accumulation of heavy metals in the non-glandular trichome?We use Arabidopsis thaliana and Chinese cabbage as research materials.Firstly,we investigated the distribution of Cd2+in plant leaves and non-glandular trichome;then we explored the effect of trichome on Arabidopsis thaliana and Chinese cabbage tolerance to Cd2+;and the influence of touching the non-glandular trichome on its detoxification function was checked.The results are as following:1.Cd2+in Arabidopsis thaliana and Chinese cabbages leaves accumulated trichome firstly.2 Arabidopsis thaliana trichomes increase cadmium tolerance compare with glabrous gll-1 mutant.The content of Cd2+ in the leaves of the wild type is lower than in leaves of glabrous mutant.3.The cadmium content in Chinese cabbage leaves is related to the leaf age,and the cadmium content in in young leaves is lower than that old leaves.4.Touching non-glandular trichome accelerates the accumulation of Cd2+in the plant hair,and the content and the distribution of Cd2+in the leaves were changed.Cd2+in crops,such as grains,vegetables,oils,and Chinese herbal medicines,will be transferred to the human diet through the food chain.Because Cd2+preferentially accumulate on the non-glandular trichomes,therefore we monitor the accumulation of heavy metals in the early planting of crops to prevent heavy metals pollution in agricultural products.Touching the non-glandular trichome increases the heavy metal content of the soil remediation plants and thus enhances the phytoextraction capacity of plants.