Variable content and distribution of arabinogalactan proteins in banana (Musa spp.) under low temperature stress

Abstract

Information on the spatial distribution of arabinogalactan proteins (AGPs) in plant organs and tissues during plant reactions to low temperature (LT) is limited. In this study, the extracellular distribution of AGPs in banana leaves and roots, and their changes under LT stress were investigated in two genotypes differing in chilling tolerance, by immuno-techniques using 17 monoclonal antibodies against different AGP epitopes. Changes in total classical AGPs in banana leaves were also tested. The results showed that AGP epitopes recognized by JIM4, JIM14, JIM16, and CCRC-M32 antibodies were primarily distributed in leaf veins, while those recognized by JIM8, JIM13, JIM15, and PN16.4B4 antibodies exhibited predominant sclerenchymal localization. Epitopes recognized by LM2, LM14, and MAC207 antibodies were distributed in both epidermal and mesophyll cells. Both genotypes accumulated classical AGPs in leaves under LT treatment, and the chilling tolerant genotype contained higher classical AGPs at each temperature treatment. The abundance of JIM4 and JIM16 epitopes in the chilling-sensitive genotype decreased slightly after LT treatment, and this trend was opposite for the tolerant one. LT induced accumulation of LM2- and LM14-immunoreactive AGPs in the tolerant genotype compared to the sensitive one, especially in phloem and mesophyll cells. These epitopes thus might play important roles in banana LT tolerance. Different AGP components also showed differential distribution patterns in banana roots. In general, banana roots started to accumulate AGPs under LT treatment earlier than leaves. The levels of AGPs recognized by MAC207 and JIM13 antibodies in the control roots of the tolerant genotype were higher than in the chilling sensitive one. Furthermore, the chilling tolerant genotype showed high immuno-reactivity against JIM13 antibody. These results indicate that several AGPs are likely involved in banana tolerance to chilling injury.

Expression and distribution of extensins and AGPs in susceptible and resistant banana cultivars in response to wounding and Fusarium oxysporum

“…In addition, similar set of antibodies were used to investigate the distribution of their epitopes in banana roots, somatic embryos and leaves. The results showed that some epitopes, such as those recognized by JIM11, JIM13, JIM16, JIM20, LM2 and LM14 appeared in both roots and leaves, but some others, such as JIM4 and MAC204 binding AGPs, were differentially expressed in roots or leaves 27 28 39 . This indicated that AGPs are organ specific.…”

“…AGP and extensin recognizing antibodies used for immunofluorescence labelling were the same as in Yan et al . 39 and Xie et al . 10 respectively.…”

Hydroxyproline-Rich Glycoproteins as Markers of Temperature Stress in the Leaves of Brachypodium distachyon

“…Despite many studies on the role of AGP in plant development, our understanding of their role in the reaction of the plant to temperature stress is still quite limited. Recent studies have shown that temperature stress strongly affects the distribution and content of AGP in the stigma and ovule of Solanum lycopersicum as well as in banana leaves and roots, which may indicate that AGP are differentially regulated in the response to temperature stress and that their expression and distribution is tissue specific [16,17,18].…”

Genome-Wide Identification, Phylogeny, and Expression Analyses of the 14-3-3 Family Reveal Their Involvement in the Development, Ripening, and Abiotic Stress Response in Banana

“…Banana fruit quality is determined by development and postharvest ripening processes and it plays an important role in the commodity economy (Raza et al, 2016 ). Also, banana production is often threatened by various environmental stresses such as low temperature, drought, salt damage, and various diseases (Ravi et al, 2013 ; Yan et al, 2015 ; Yang et al, 2015 ; Raza et al, 2016 ). Thus, it is necessary to study the molecular mechanism underlying banana fruit development, postharvest ripening, and response to various abiotic stresses.…”