Immunohistochemical Localization of Endogenous IAA in Peach (Prunus persica L.) Fruit during Development

Abstract

Peach (Prunus persica L.) is a model species for stone fruit studies within the Rosaceae family. Auxin plays an important role in the development of peach fruit. To reveal the distribution of auxin in the tissues of peach fruit, immunohistochemical localization of IAA was carried out in the seed, mesocarp, and endocarp in developing peach fruit using an anti-indole-3-acetic acid (anti-IAA) monoclonal antibody. A strong IAA signal was observed throughout the outer and inner integument during peach fruit development, and the distribution was zonal. The IAA signal was mainly focused in mucilage layers in the outer integument. The outer integument may function to produce or store IAA in the seed; a strong IAA signal was detected in the cells around the vascular tissue, whereas a weak IAA signal was located in the vascular tissues. In the mesocarp, the cells around the vascular bundle tissue gave rise to an IAA signal that increased in the late phase of fruit growth, which coincided with a significant increase in fruit growth. The distribution of IAA, however, was changed when fruit was treated with auxin transport inhibitors NPA (1-N-naphthylphthalamic acid) or TIBA (2, 3, 5-triiodobenzoic acid); in mesocarp tissues, an IAA signal was detected mainly in vessels of the treated fruit. During the critical period of endocarp lignification, the vessel lignification process was negatively correlated with IAA signal. The present results confirmed that the distribution of IAA was different in various tissues of peach fruit according to the developmental stage. This research provides cytological data for further study of the regulatory mechanism of auxin in peach fruit.Additional key words: Endocarp, Mesocarp, NPA, Outer and inner integument, TIBA

PbrmiR397a regulates lignification during stone cell development in pear fruit

“…In fact, most plant hormones affect the lignin biosynthesis pathway. Auxin negatively regulates vessel lignification during peach endocarp lignification (Zhang et al ., ). Also, decreased levels of cytokinin in response to the reduced expression of ABCG14 , a newly identified cytokinin transporter, lead to delayed lignin biosynthesis and reduced numbers of lignified cells (Zhang et al ., ).…”

Immunolocalization of Endogenous Indole-3-Acetic Acid and Abscisic Acid in the Shoot Internodes of Fargesia yunnanensis Bamboo during Development

“…Auxin is important for the induction of vascular tissue development (Sieburth, 1999). Dong et al (2012) surrounding the vascular tissues in peach (Prunus persica; Zhang et al, 2015). According to the subcellular localization of endogenous IAA during shoot internode elongation, the internode development process could be divided into two developmental stages, i.e., the differentiation and elongation stage and the maturation stage.…”

“…IAA is the most abundant naturally occurring auxin and is involved in many aspects of plant growth and development, such as cell division and elongation, differentiation, tropism, apical dominance, senescence, abscission, and flowering (Chudasama and Thaker, 2007;Mano and Nemoto, 2012;Teale et al, 2006;Woodward and Bartel, 2005). To date, a large number of studies have focused on the role of auxin in rhizogenesis (Dong et al, 2012(Dong et al, , 2014Falasca et al, 2004;Gangopadhyay et al, 2010;Ludwig-Muller et al, 2005;Xuan et al, 2008), embryogenesis and development (Chen et al, 2010;Thomas et al, 2002;Zhang et al, 2015), and floral induction (Hou and Huang, 2005).…”