Molecular control of crop shade avoidance

Abstract

The shade avoidance response (SAR) in crops can be detrimental to yield, as precious carbon resources are redirected to stem or petiole elongation at the expense of biomass production. While breeding efforts have inadvertently attenuated this response in staple crops through correlated selection for yield at high density, it has not been eliminated. The extensive work done in Arabidopsis has provided a detailed understanding of the SAR and can be used as a framework for understanding the SAR in crop species. Recent crop SAR works point to auxin as a key factor in regulating the SAR in several crop species. These works also clearly demonstrate that one model for crop SAR will not fit all, and thus we need to move forward with studying the genetic players of the SAR in several model crop species. In this review, we provide the current knowledge of the SAR as reported at the physiological and molecular levels.

Linking PHYTOCHROME-INTERACTING FACTOR to Histone Modification in Plant Shade Avoidance

“…Although much had been learned from both the input pathway perceiving shade and multiple output pathways involving phytohormone production/signaling in SAS (Casal, 2012;Carriedo et al, 2016;Ballaré and Pierik, 2017), how transcription of multiple genes is coordinately induced within the chromatin context in response to shade had been largely obscure. Our current study demonstrates that PIF7 recruits the H3K4me3/ H3K36me3-reader MRG2 (possibly also MRG1 because The conserved domains APB and bHLH are indicated as red and black box, respectively.…”

“…A classical SAS phenotype includes elongation of hypocotyls, stems, petioles, or internodes; hyponastic leaves; reduced leaf lamina size; enhanced apical dominance; and/or early flowering (Casal, 2012;Ballaré and Pierik, 2017). Because of cultivable land limitation, crops are planted at a high density in modern agriculture, and if activated, SAS will decrease the crop yield (Carriedo et al, 2016;Ballaré and Pierik, 2017). Thus, understanding the mechanisms underlying SAS has prevalent importance for both natural ecosystem and agricultural breeding interests.…”

Molecular Profiles of Contrasting Shade Response Strategies in Wild Plants: Differential Control of Immunity and Shoot Elongation

“…Currently, it remains unknown how shade tolerant species inhibit SAS while being exposed to potent SAS-inducing light signals . Identifying the molecular mechanisms underpinning suppression of SAS has great potential to (1) show how different strategies of adaptive plasticity can be regulated and (2) inform crop-breeding programs targeted at minimizing yield losses, which are caused by wasteful carbon investments in nonharvestable stems (Carriedo et al, 2016) and suppressed immunity.…”

Caracterização do relógio biológico e seu impacto no metabolismo da cana-de-açúcar

“…As evidências de presença de SAR são bastante claras e envolvem estratégias adaptativas desenvolvidas pela planta para responder ao sombreamento: redução de ramificação; aumento na altura da planta via elongação do caule; redução do número de folhas; alteração da relação folha:pecíolo e, como consequência deste conjunto, redução de produção de biomassa (Carriedo et al, 2016;Roig-villanova & Martínez-garcía, 2016). Particularmente no caso de gramíneas, a SAR provoca redução de perfilhamento (Carriedo et al, 2016). Entretanto, ao longo da domesticação das gramíneas agricultáveis, foram selecionadas plantas adaptadas à alta densidade populacional no campo (Wang et al, 1999 …”

“…O crescimento das plantas é otimizado nas câmaras de crescimento ou nas casas de vegetação, assim como maior área foliar, embora sejam menores em tamanho, já que a duração dos experimentos aos quais são submetidas é reduzida (Poorter et al, 2016). Além disso, a densidade de plantas é reduzida nas planta crescidas em câmaras de crescimento ou casas de vegetação, de modo que efeitos de sombreamento não são observados, muito menos Shade Avoidance Response (SAR) (Carriedo et al, 2016); (Poorter et al, 2016); (Roig-Villanova & Martínez-García, 2016).…”