Pivotal Roles of Cryptochromes 1a and 2 in Tomato Development and Physiology

Abstract

Cryptochromes are flavin-containing blue/UVA light photoreceptors that regulate various plant light-induced physiological processes. In Arabidopsis (Arabidopsis thaliana), cryptochromes mediate de-etiolation, photoperiodic control of flowering, entrainment of the circadian clock, cotyledon opening and expansion, anthocyanin accumulation, and root growth. In tomato (Solanum lycopersicum), cryptochromes are encoded by a multigene family, comprising CRY1a, CRY1b, CRY2, and CRY3. We have previously reported the phenotypes of tomato cry1a mutants and CRY2 overexpressing plants. Here, we report the isolation by targeting induced local lesions in genomes, of a tomato cry2 knockout mutant, its introgression in the indeterminate Moneymaker background, and the phenotypes of cry1a/cry2 single and double mutants. The cry1a/cry2 mutant showed phenotypes similar to its Arabidopsis counterpart (long hypocotyls in white and blue light), but also several additional features such as increased seed weight and internode length, enhanced hypocotyl length in red light, inhibited primary root growth under different light conditions, anticipation of flowering under long-day conditions, and alteration of the phase of circadian leaf movements. Both cry1a and cry2 control the levels of photosynthetic pigments in leaves, but cry2 has a predominant role in fruit pigmentation. Metabolites of the sterol, tocopherol, quinone, and sugar classes are differentially accumulated in cry1a and cry2 leaves and fruits. These results demonstrate a pivotal role of cryptochromes in controlling tomato development and physiology. The manipulation of these photoreceptors represents a powerful tool to influence important agronomic traits such as flowering time and fruit quality.

Green light reduces elongation when partially replacing sole blue light independently from cryptochrome 1a

“…A yet unknown green light photoreceptor may exist in plants. While the cryptochrome family has been well studied in the model plant Arabidopsis, information about the crys is limited in crop plants, such as tomato, that have an architecture very different from that of Arabidopsis (Liu et al, 2018;Fantini et al, 2019).…”

Genome-wide study of pineapple (Ananas comosus L.) bHLH transcription factors indicates that cryptochrome-interacting bHLH2 (AcCIB2) participates in flowering time regulation and abiotic stress response

“…One of the essential class of photo-receptors involved in flowering initiation is cryptochromes (CRYs) and their interacting proteins; cryptochrome-interacting bHLH proteins (CIBs) [ 18 ]. Most of the photoreceptors signaling mechanisms have been reported in Arabidopsis [ 15 ], and recently in tomato [ 17 ]. CRY2-CIB network in plants decodes an excellent pathway for modulating light signal during photomorphogenesis.…”

“…Plants encode numerous photo-receptors that participate in light signaling and regulate many aspects of growth and development [14]. Several photoreceptors have been reported in plants, including cryptochromes, phytochromes, phototropins, UV Resistance locus 8 (UVR8), and Zeitlupe family members (ZTL, FKF1, and LKP2) [15][16][17]. CRYs are photolyase-associated blue-light receptors, and they interact with different proteins in the presence of bluelight to mediate a plethora of functions, such as inhibition of hypocotyl elongation and flowering initiation [9,[18][19][20].…”

“…CRYs are photolyase-associated blue-light receptors, and they interact with different proteins in the presence of blue-light to mediate a plethora of functions, such as inhibition of hypocotyl elongation and flowering initiation [ 9 , 18 – 20 ]. In Arabidopsis , three cryptochromes are encoded: cryptochrome 1 (CRY1), cryptochrome 2 (CRY2), and cryptochrome 3 (CRY3) [ 14 , 17 , 21 , 22 ]. CRY1 participates in blue light-dependent de-etiolation responses and inhibition of hypocotyl elongation.…”

A Mutation in CsHY2 Encoding a Phytochromobilin (PΦB) Synthase Leads to an Elongated Hypocotyl 1(elh1) Phenotype in Cucumber (Cucumis sativus L.)

“…Light is among the most important environmental cues controlling plant growth and development such as seed germination, cotyledon expansion, hypocotyl elongation, root growth, owering and fruit set (Pham et al 2018;Seo et al2019;Huai et al 2020;Liu et al 2021). Plant perceives lights by a suite of photoreceptors including phytochromes (for red and far-red light) (Oh et al 2020;Kahle et al 2020), cryptochromes and phototropins (for blue/UVA light) (Sztatelman et al 2016;Fantini et al 2019;Lin et al 2019) and UVR8 (for UVB) (Zhao et al 2016;Tavridou et al 2020;Yang et al 2020). Among them, the best characterized are the phytochromes (phys), which regulate a wide range of light responses from seed germination to owering (Josse et al 2008;Montgomery.…”