Uptake, Translocation, Metabolism, and Distribution of Glyphosate in Nontarget Tea Plant (<i>Camellia sinensis</i> L.)

The uptake, translocation, metabolism, and distribution behavior of glyphosate in nontarget tea plant were investigated. The negative effects appeared to grown tea saplings when the nutrient solution contained glyphosate above 200 mg L^–1. Glyphosate was highest in the roots of the tea plant, where it was also metabolized to aminomethyl phosphonic acid (AMPA). The glyphosate and AMPA in the roots were transported through the xylem or phloem to the stems and leaves. The amount of AMPA in the entire tea plant was less than 6.0% of the amount of glyphosate. The glyphosate level in fresh tea shoots was less than that in mature leaves at each day. These results indicated that free glyphosate in the soil can be continuously absorbed by, metabolized in, and transported from the roots of the tea tree into edible leaves, and therefore, free glyphosate residues in the soil should be controlled to produce teas free of glyphosate

L'Auto-vélo : automobilisme, cyclisme, athlétisme, yachting, aérostation, escrime, hippisme / dir. Henri Desgranges

23 novembre 19231923/11/23 (A24,N8378)

Genes and corresponding primers used for the RT-qPCR experiments.

<p>Genes and corresponding primers used for the RT-qPCR experiments.</p

Comparative analysis of the response and gene regulation in cold resistant and susceptible tea plants

<div><p>Cold environment is the main constraint for tea plants (<i>Camellia sinensis</i>) distribution and tea farming. We identified two tea cultivars, called var. <i>sinensis</i> cv. <i>Shuchazao</i> (SCZ) with a high cold-tolerance and var. <i>assamica</i> cv. <i>Yinghong9</i> (YH9) with low cold-tolerance. To better understand the response mechanism of tea plants under cold stress for improving breeding, we compared physiological and biochemical responses, and associated genes expression in response to 7-day and 14-day cold acclimation, followed by 7-day de-acclimation in these two tea cultivars. We found that the low EL50, low Fv/Fm, and high sucrose and raffinose accumulation are responsible for higher cold tolerance in SCZ comparing with YH9. We then measured the expression of 14 key homologous genes, known as involved in these responses in other plants, for each stages of treatment in both cultivars using RT-qPCR. Our results suggested that the increased expression of <i>CsCBF1</i> and <i>CsDHNs</i> coupling with the accumulation of sucrose play key roles in conferring higher cold resistance in SCZ. Our findings have revealed key genes regulation responsible for cold resistance, which help to understand the cold-resistant mechanisms and guide breeding in tea plants.</p></div

Effects of cold treatment on proline accumulation in tea cultivars.

<p>Data are displayed as the mean of three replicates and standard error. Columns with different letters had significant differences according to Duncan’s multiple range tests with <i>P</i> < 0.05. SCZ and YH9 represent tea cold resistant and cold susceptible tea varieties, respectively. NA: non-acclimation; CA1: cold acclimation of 7 days at 10/4°C, day/night temperature; CA2: cold acclimation of 7 days at 4/0°C, day/night temperature; DA: de-acclimation of 7 days at 25/20°C, day/night temperature.</p