Modelling plant resource allocation and growth partitioning in response to environmental heterogeneity

Fire is a natural part of most Australian landscapes and has an important influence on the biological productivity and biotic composition of many ecosystems. Although fire is commonly used as a management tool, the precise nature of the way it may influence productivity and biotic composition is often poorly understood and, as a consequence, its use is controversial. This paper considers the use of fire for the management of ecosystems. Specifically, the influences of fire on environmental heterogeneity and the effects these have on shaping biological productivity and biotic patterns are discussed. Heterogeneity that affects biotic response includes variation in biophysical attributes of landscapes such as topography, fire regimes and the spatial attributes of fire. Examples are used to address the interplay between fires, environmental heterogeneity and biological patterns: (1) the effects of frees on plant resource availability; (2) crown scorch in eucalypt forests; and (3) the effects of spatial variation (patchiness) within a fire on species composition. Heterogeneity should be considered explicitly in management because prescriptions devised elsewhere may not be able to be imported with confidence to all sites and the responses of the biota to fires may differ from available information. Ecological monitoring and research into the ecological effects of heterogeneity are required to provide a predictive understanding of natural systems and provide information to aid decisions about the use of fire as a management tool.

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Trehalose 6-phosphate signalling and impact on crop yield

Biochemical Society Transactions ◽

10.1042/bst20200286 ◽

2020 ◽

Vol 48 (5) ◽

pp. 2127-2137

Author(s):

Matthew J. Paul ◽

Amy Watson ◽

Cara A. Griffiths

Keyword(s):

Resource Allocation ◽

Grain Yield ◽

Green Revolution ◽

Regulatory System ◽

Grain Filling ◽

Stem Height ◽

Grain Number ◽

Plant Resource ◽

Whole Plant ◽

Source Sink

The domestication and breeding of crops has been a major achievement for mankind enabling the development of stable societies and civilisation. Crops have become more productive per unit area of cultivated land over the course of domestication supporting a current global population of 7.8 billion. Food security crops such as wheat and maize have seen large changes compared with early progenitors. Amongst processes that have been altered in these crops, is the allocation of carbon resources to support larger grain yield (grain number and size). In wheat, reduction in stem height has enabled diversion of resources from stems to ears. This has freed up carbon to support greater grain yield. Green revolution genes responsible for reductions in stem height are known, but a unifying mechanism for the active regulation of carbon resource allocation towards and within sinks has however been lacking. The trehalose 6-phosphate (T6P) signalling system has emerged as a mechanism of resource allocation and has been implicated in several crop traits including assimilate partitioning and improvement of yield in different environments. Understanding the mode of action of T6P through the SnRK1 protein kinase regulatory system is providing a basis for a unifying mechanism controlling whole-plant resource allocation and source-sink interactions in crops. Latest results show it is likely that the T6P/SnRK1 pathway can be harnessed for further improvements such as grain number and grain filling traits and abiotic stress resilience through targeted gene editing, breeding and chemical approaches.

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Digest: Linking coordinated shifts in plant resource allocation to a chromosomal inversion*

Evolution ◽

10.1111/evo.13751 ◽

2019 ◽

Vol 73 (6) ◽

pp. 1318-1319

Author(s):

Steven Dodsworth ◽

Oscar A. Pérez‐Escobar

Keyword(s):

Resource Allocation ◽

Chromosomal Inversion ◽

Plant Resource

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Resource Allocation to Asexual Gemma Production and Sexual Reproduction in South-Western Australian Pygmy and Micro Stilt-Form Species of Sundew (Drosera spp, Droseraceae)

Australian Journal of Botany ◽

10.1071/bt9920353 ◽

1992 ◽

Vol 40 (3) ◽

pp. 353 ◽

Cited By ~ 12

Author(s):

PS Karlsson ◽

JS Pate

Keyword(s):

Resource Allocation ◽

Sexual Reproduction ◽

Seed Production ◽

Asexual Reproduction ◽

Western Australia ◽

Dry Matter ◽

Late Season ◽

Plant Resource ◽

Total Plant ◽

Western Australian

Proportional allocations of current total dry matter (DM), N and P to early season asexual gemma production and late-season flowering and seed production were compared for eight pygmy rosette form and three micro stilt-form perennial pygmy sundews (Drosera spp.) in native habitat in south-western Australia. Mean allocations to gemmae for the smaller rosette species were 22% for DM, 60% for N and 38% for P versus 8, 20 and 23% (DM, N, P) respectively for the micro stilt forms. Allocations to mature fully formed seeds were extremely low, 1-8, 4.0 and 5.4% (DM, N, P) for the rosette forms, 0.7, 3-0 and 2.3% respectively for the micro stilt forms. The above values reflect the heavy bias towards gemma production, (8-52 propagules per plant per season across the 11 species) as opposed to that for seed (0-8 fully formed seeds per plant per season). Comparable information for the annual nongemmiferous pygmy sundew D. glanduligera showed end of season allocation of 66, 37 and 29% (DM, N, P) of total plant resource to inflorescences minus seeds, and additional amounts equivalent to 30, 59 and 69% to the 60 seeds produced per plant of this species in the study season. A detailed phenology of resource allocation across a full season of growth in second, third and fourth season plants of the rosette perennial D. closterostigma showed net seasonal losses in the total vegetative resource of N and of P in older plants attributable to apparent over commitment to asexual reproduction during the season of study.

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