Phytochrome B enhances plant growth, biomass and grain yield in field-grown maize

Abstract

Background and Aims Phytochrome B (phyB) is a photosensory receptor important for the control of plant plasticity and resource partitioning. Whether phyB is required to optimize plant biomass accumulation in agricultural crops exposed to full sunlight is unknown. Here we investigated the impact of mutations in the genes that encode either phyB1 or phyB2 on plant growth and grain yield in field crops of Zea mays sown at contrasting population densities.• Methods Plants of maize inbred line France 2 wild type (WT) and the isogenic mutants lacking either phyB1 or phyB2 (phyB1 and phyB2) were cultivated in the field during two seasons. Plants were grown at two densities (9 and 30 plants m -2 ), irrigated and without restrictions of nutrients. Leaf and stem growth, leaf anatomy, light interception, above-ground biomass accumulation and grain yield were recorded.• Key Results At high plant density, all the lines showed similar kinetics of biomass accumulation. However, compared with the WT, the phyB1 and phyB2 mutations impaired the ability to enhance plant growth in response to the additional resources available at low plant density. This effect was largely due to a reduced leaf area (fewer cells per leaf), which compromised light interception capacity. Grain yield was reduced in phyB1 plants.• Conclusions Maize plants grown in the field at relatively low densities require phyB1 and phyB2 to sense the light environment and optimize the use of the available resources. In the absence of either of these two light receptors, leaf expansion is compromised, imposing a limitation to the interception of photosynthetic radiation and growth. These observations suggest that genetic variability at the locus encoding phyB could offer a breeding target to improve crop growth capacity in the field.

He-Ne Laser Seed Treatment Improves the Nutraceutical Metabolic Pool of Sunflowers and Provides Better Tolerance Against Water Deficit

“…These findings indicate that the variety used has moderate drought tolerance. The enhanced achene number and weight in treated plants are in agreement with Wies et al (2019). They provided evidence of a direct correlation between light-induced phytochrome activation and leaf expansion, photosynthetic efficiency, biomass, leaf area, and grain yield.…”

Regulation of monocot and dicot plant development with constitutively active alleles of phytochrome B

“…In view of the importance of phyB to plant growth, biomass and crop yield in major crop plants such as maize for example (Wies, Mantese, Casal, & Maddonni, 2019), we envisage a number of applications for crop plant improvement with novel PHYB alleles, for example, suppression of SARs, alteration of shoot and root dormancy, tillering, tuberization, among other phyB‐dependent processes. As dominant missense alleles, YHBs should be feasible to generate in the native chromosomal context by CRISPR‐Cas technology to yield new varieties of “unconventionally bred” elite crop lines without alteration of other loci.…”

Neighbour signals perceived by phytochrome B increase thermotolerance in Arabidopsis

“…Taken together with the enhanced tolerance to heat stress reported here and elsewhere (Song et al, ), these observations indicate that the phyB mutant is less susceptible to both temperature extremes. It appears that phytochrome mutants are less affected by growth‐restricting abiotic stresses at the cost of reduced growth in the absence of stress (Wies, Mantese, Casal, & Maddonni, ; Yang, Seaton, Krahmer, & Halliday, ).…”