Non-structural Carbohydrates in Dormant Woody Perennials; The Tale of Winter Survival and Spring Arrival

Abstract

Woody perennials' reliance on nonstructural carbohydrates (NSC) reserves for the resumption of spring growth necessitates an accumulation of NSC prior to dormancy. It is assumed that during dormancy temperature-regulated biological activities gauge the progression of winter and affect the metabolic rates and physiology of NSC reserves. Thus, changes in temperature signal the arrival of spring and determine the amount of reserves available for growth resumption. As woody perennials are dependent on dispersed storage of NSC during spring, they need an integrated remobilization and redistribution for synchronous and effective development of photosynthetic and reproductive organs. However, it is not known how storage compartments interact at the whole plant level, when NSC reserves are mobilized, or how local and distal storage compartments influence the biology of spring growth resumption. The goal of this mini-review is to shift the focus of winter biology from bud-centric to the whole plant. We discuss winter NSC management in the context of climate change with a special emphasis on how projected mild winters may affect the carbon budget, transport, and allocation during winter. We look at three aspects of NSC regulation underlying dormancy (I) the molecular regulation of dormancy (II) temperature dependent winter NSC metabolism, and (III) spring NSC remobilization and redistribution processes.

Comparison of phenological traits, growth patterns, and seasonal dynamics of non-structural carbohydrate in Mediterranean tree crop species

“…The observations of these spatial gradients of total NSC concentration in pistachio and almond trees during low fruit bearing years and their absence during high fruit bearing years support this hypothesis 40,43 . In the context of increasing winter temperatures and higher frequency of frost-thaw events, higher NSC demand during dormancy may overall lead to a general reduction of these crucial reserves for spring growth which would weaken reproduction capacity and growth 44 .…”

“…In each panel, red asterisks indicate the significance of the smooth term describing Doy effect (at *P < 0.05, **P < 0.01, or ***P < 0.001 for Twig /Branch/Trunk, in this order; ns, not significant). that effect of phenological events are buffered by the compartment size, meaning that larger organ size and higher relative contribution of storage cells in wood would attenuate any sudden response and explain discrepancies between species and organs 44,53 . Indeed, higher storage capacity infers higher inertia and momentum 15 .…”

Distinctive Gene Expression Patterns Define Endodormancy to Ecodormancy Transition in Apricot and Peach

“…The activity of a-amylase which hydrolases starch into sucrose is reported to increase after floral and vegetative buds release from endodormancy (Hussain et al, 2015). To resume growth from dormancy, buds not only use local sugars, but also transport carbohydrates from long distances (Tixier et al, 2019). Tixier et al (2017) propose long-distance sugar transport in walnut sustains the fast growth resumption after dormancy release (Tixier et al, 2017).…”

The Possible Role of Non-Structural Carbohydrates in the Regulation of Tree Hydraulics

“…Although several studies have underlined the importance of NSCs for maintaining hydraulic integrity under fluctuating water availability, a complete mechanistic picture of the processes In our survey we could not identify any relationship between hydraulic parameters and total NSCs or starch contents in the recovery phase. The stored starch content pools in stems are strictly dependent on the species-specific stem anatomical features such as wood parenchyma fraction [120], phenology, period of the year, length of the stress and in general by the environmental stress conditions previously faced by the plant [118,125]. Moreover, in some species lipids are accumulated instead of starch [9,124].…”