The crosstalk between Target of Rapamycin (TOR) and Jasmonic Acid (JA) signaling existing in Arabidopsis and cotton

Abstract

Target of rapamycin (TOR) acts as an important regulator of cell growth, development and stress responses in most examined diploid eukaryotes. However, little is known about TOR in tetraploid species such as cotton. Here, we show that TORC1-S6K-RPS6, the major signaling components, are conserved and further expanded in cotton genome. Though the cotton seedlings are insensitive to rapamycin, AZD8055, the second-generation inhibitor of TOR, can significantly suppress the growth in cotton. Global transcriptome analysis revealed that genes associated with jasmonic acid (JA) biosynthesis and transduction were significantly altered in AZD8055 treated cotton seedlings, suggesting the potential crosstalk between TOR and JA signaling. Pharmacological and genetic approaches have been employed to get further insights into the molecular mechanism of the crosstalk between TOR and JA. Combination of AZD8055 with methyl jasmonate can synergistically inhibit cotton growth, and additionally JA levels were significantly increased when cotton seedlings were subjected to AZD8055. JA biosynthetic and signaling mutants including jar1, coi1-2 and myc2-2 displayed TOR inhibitor-resistant phenotypes, whereas COI1 overexpression transgenic lines and jaz10 exhibited sensitivity to AZD8055. Consistently, cotton JAZ can partially rescue TOR-suppressed phenotypes in Arabidopsis. These evidences revealed that the crosstalk between TOR and JA pathway operates in cotton and Arabidopsis.

Target of rapamycin signaling orchestrates growth–defense trade‐offs in plants

“…Consistent with recent findings in A. thaliana (Dong et al, 2015;Song et al, 2017), we found that pharmacological and genetic disruption of TOR strongly boosts SA and JA responses in rice. Given the paramount importance of both hormones in orchestrating myriad defense reactions, these findings support the notion that TOR restricts plant immunity, at least in part, by antagonizing SA and JA.…”

The TOR Pathway Is Involved in Adventitious Root Formation in Arabidopsis and Potato

“…Researches in Arabidopsis, Zea mays, Gossypium hirsutum, Solanum lycopersicum , and Chlamydomonas creinhardtii showed that TOR signaling played fundamental roles in seed germination, root and leaf growth, flowering, senescence, and life-span determination in plants (Crespo et al, 2005; Agredano-Moreno et al, 2007; Song et al, 2007; Ren et al, 2011, 2012; Xiong et al, 2013, 2016; Xiong and Sheen, 2014) but little is known about the role of TOR signaling in adventitious root formation in plants.…”

TOR signaling system in plants

“…Показаны, что TOR из разных видов растений имеют высокое сходство аминокислотных последовательностей с TOR млекопитающих и дрожжей, особенно в киназной и FRB доменах. В геноме Gossypium hirsutum выявлено, что гены TOR киназы хлопчатника представлена в двух генетических локусах GhTOR1 и GhTOR2 [14]. Полноразмерная последовательность гена GhTOR1 состоит из 20,012 п.н.…”

“…Некоторые эксперименты по изучения влияния рапамицина на растительные организмы показали, что высшие растения устойчивы к низким концентрациям данного макролида, в отличие от одноклеточных водорослей [4,7,11,13,14,28,29,30,31]. Авторы не исключают вероятность селективного преимущества мутации в гене F�BP12 растений, чтобы противостоять по-TOR сигнальная система в растениях чвенному стрептомицету, который продуцирует рапамицин [32].…”