Multiple Consequences Induced by Epidermally-Located Anthocyanins in Young, Mature and Senescent Leaves of Prunus

Abstract

Anthocyanic morphs are generally less efficient in terms of carbon gain, but, in turn, are more photoprotected than anthocyanin-less ones. To date, mature leaves of different morphs or leaves at different developmental stages within the same species have generally been compared, whereas there is a lack of knowledge regarding different stages of development of red vs. green leaves. Leaves (1-, 7-, and 13-week-old) of red- (RLP) and green-leafed (GLP) Prunus in terms of photosynthetic rate, carbon metabolism and photoprotective mechanisms were compared to test whether anthocyanin-equipped leaves perform better than anthocyanin-less leaves and whether photoprotection is the primary role of epidermally-located anthocyanins, using for the first time a recently-developed parameter of chlorophyll fluorescence (qPd). GLP leaves had a higher photosynthetic rate in 1- and 7-week-old leaves, but RLP leaves performed better at an early stage of senescence and had a longer leaf lifespan. Anthocyanins contributed to leaf photoprotection throughout the leaf development, but were tightly coordinated with carotenoids. Besides photoprotecting, we propose that epidermal anthocyanins may be principally synthetized to maintain an efficient carbon-sink strength in young and senescent leaves, thus extending the RLP leaf lifespan.

Boron toxicity in higher plants: an update

“…Therefore, changes in sugar content and partitioning (Roessner et al 2006;Papadakis et al 2018), as well as in carbon skeleton devoted to aminoacids, which are strictly interlinked (Guo et al 2014) can be observed as a response to B excess (Sang et al 2015;Ayvaz et al 2016). An imbalance of C/N ratio also promote phenomena of early senescence (Lo Piccolo et al 2018;Sotiras et al 2019) and this explains the enhancement of senescence-related hormones i.e. jasmonic acid and ethylene promoted by B excess in barley and wheat (Öz et al 2009;Kayıhan et al 2017).…”

Special issue in honour of Prof. Reto J. Strasser - Development and aging of photosynthetic apparatus of Vitis vinifera L. during growing season

“…Lo Piccolo et al (2018) found that the Chl content increased in mature leaves and significantly decreased toward the end of the experiment. These typical Chl content changes during lifespan of leaves were confirmed by many other authors (Lu et al 2001(Lu et al , 2002Weng et al 2005, Table 1.…”

“…4). Lo Piccolo et al (2018) found that anthocyanin content showed an inversed course of changes compared to Chl, but did not reach the values of juvenile leaves. However, we found that anthocyanins content both at the beginning and at the end of leaf lifespan were comparable and statistically insignificant (Fig.…”

“…The changes of photosynthetic apparatus are naturally associated with the dynamics of Chl content in leaves. Both, Jiang et al (2006a,b) andLo Piccolo et al (2018) demonstrated the increase of minimal fluorescence (F0) and maximum quantum yield of primary photochemistry (φP0) with the young leaves development. Moreover, Jiang et al (2006a) showed that with leaf development, the efficiency that a trapped exciton can move an electron into the electron transport chain further than QA (Ψ0) and the quantum yield of electron transport beyond QA (φE0), increased gradually and rapidly.…”

“…Different flavonoid subclasses have been found to possess protective roles in plant tissues and the biosynthesis of flavonoids often increases in response to biotic and abiotic stress factors (Jaakola et al 2004). Anthocyanins play mostly a photoprotective role in leaves, trapping the excessive light radiation, but may also offer an alternative way of reducing the accumulation of hexoses, thus delaying the sugar-induced early senescence of leaves (Landi et al 2015, Lo Piccolo et al 2018. Flavonols have been found to play a protective role as a UV filter, but may also participate in a peroxidase-flavonol quenching system for reactive oxygen species (Jaakola et al 2004, Skórzyńska-Polit et al 2004.…”