Short Communication Proline accumulation is a general response to abiotic stress in the date palm tree (Phoenix dactylifera L.)

Abstract

ABSTRACT. Plants exposed to certain abiotic stress conditions tend to produce the amino acid proline, which acts as an active osmolyte, a metal chelator, an antioxidant, and a signaling molecule. There is increasing evidence that proline accumulates in plants due to a wide range of abiotic stress, in particular high soil salinity and drought. Therefore, proline content is often used as a marker-assisted breeding tool aimed at improving drought and salinity tolerance. In this study, it was investigated whether proline accumulation in date palm (Phoenix dactylifera L.) seedlings occurs solely due to high salinity and drought stresses or due to other unspecified abiotic stresses, including salinity and salinity shock, drought, extreme temperatures, and abscisic acid. The free proline assays revealed that this amino acid over-accumulated in the roots and leaves of each stresstreated plant, and was remarkably high when leaves were exposed to suboptimum temperatures and salinity stress. These results indicate that the production of proline is a common response to various abiotic stresses and its differential accumulation cannot be used as a molecular marker in date palm breeding programs aimed at improving drought or salinity 9943-9950 (2015) tolerance traits in date palms. This conclusion is consistent with the theory that the molecular outcomes of abiotic stresses are often non-specific.

Proteome Analysis of Date Palm (Phoenix dactyliferaL.) under Severe Drought and Salt Stress

“…Production of proline is a common response to various abiotic stresses and its differential accumulation cannot be used as a molecular marker in date palm breeding programs aimed at improving drought or salinity tolerance traits in date palms. This conclusion is consistent with the theory that the molecular outcomes of abiotic stresses are often nonspecific [17]. …”

Responses of date palm (Phoenix dactylifera L.) callus to biotic and abiotic stresses

“…Proline generally acts as an osmolyte for osmotic adjustment, as well as stabilizing sub-cellular structures including membrane and proteins (Ashraf and Foalad, 2005;Yaish, 2015). Accumulation of free proline under salt stress has been correlated with salt tolerance; our findings are in accordance with many other results which revealed that date palm callus accumulates a significant amount of proline as a response to NaCl stress (Al-Khayri, 2002;AlMansoori and Eldeen, 2007;Jasim et al, 2010;Al-Bahrany and Al-Khayri, 2012;Yaish, 2015).…”

Influence of salicylic acid (SA) and ascorbic acid (ASA) on in vitro propagation and salt tolerance of date palm (Phoenix dactylifera L.) cv. ‘Nersy’

“…It is remarkably high when leaves are exposed to suboptimum temperatures and salinity stress. These results indicate that the production of proline is a common response to various abiotic stresses (Yaish 2015). Addition of K + to the salt containing media of date palm has reduced the absorption of Na + and also balanced ions compartmentalization.…”