Relationship between cyanogenesis and latex stability on tapping panel dryness in rubber trunk girth

Abstract

The presence of high cyanogenic glycoside concentrations may predispose plant to the tapping panel dryness (TPD). This study aimed to verify the involvement of cyanogenesis in the reduction of latex stability and in the establishment of TPD. The following parameters were evaluated in rubber tree trunk bark: concentration of cyanogenic glycosides with determination of cyanogenic potential (HCNp) and latex stability with lutoid bursting index (LBI). The study of the relationship between cyanogenesis and TPD was performed by semiquantitative comparison of hydrogen cyanide (HCN) gas released from the trunk bark under the following conditions: without (0%) and with (100%) TPD. The positive correlations between HCNp values and LBI indicate that cyanogenic glycosides present in the bark reduce latex stability, resulting in low yield due to the short duration of flow during tapping. The largest amount of HCN released by trunk bark tissues when the plant exhibits TPD symptoms strengthens the evidence of the involvement of this compound in the establishment of this condition.

Involvement of Ethylene in the Latex Metabolism and Tapping Panel Dryness of Hevea brasiliensis

“…In aggravated conditions, an irreversible-type of TPD occurs that is called brown bast TPD (BB-TPD) ( Figure 1 g–i). The latter involves histological deformation of bark due to thylosoid formation, lignified gum, and abnormal division of parenchyma cells, and may be related to a cyanogenesis process [ 12 , 13 , 14 , 15 ].…”

Curative Activity of Watery Fermented Compost Extract as a Bark Treatment against Tapping Panel Dryness

“…The tapping cut of some treated trees started to secrete latex, but the latex was immediately coagulated (high plugging index), leading to low yield due to the short duration of flow during tapping. This effect was probably due to higher cyanogenesis on the laticifers that resulted in unstable latex [10].…”

“…In the advanced stage, an irreversible type of total dryness, called bark necrosis [9] or brown bast TPD (BB-TPD), can occur [3]. The latter, which is related to a cyanogenesis process [7,10], involves histological deformation of the bark including browning, thickening, or even flaking due to thylosoid formation, lignified gum, and abnormal division of parenchyma cells [3,9].…”

Dynamic analysis of Tapping Panel Dryness in Hevea brasiliensis reveals new insights on this physiological syndrome affecting latex production

“…To date, the literature on physiological mechanism of latex agglutination is relevant and led to some functional models ( Berthelot et al., 2014 , 2016 ; Wititsuwannakul et al., 2008a , 2008b , 2008c ). Besides the role of redox metabolism, relationship between cyanogenesis and latex stability was determined at the onset of irreversible TPD ( de Faÿ et al., 2010 ; Moraes et al., 2014 ). Some authors observed an increase in TPD when latex thiol, inorganic phosphorus and pH value decreased ( Guo et al., 2016 ).…”