Proline metabolism and biosynthesis behave differently in response to boron-deficiency and toxicity in Brassica napus

In areas where soils are low in boron (B), the ability to predict B deficiency by plant analysis depends on the development of calibrated standards and offers the potential of preventing or minimising losses in seed yield. The present study aimed at establishing relationships between seed yield in winter oilseed rape (Brassica napus) and B concentrations in defined leaves during growth before fiowering and from them to determine critical values for the prognosis of B deficiency. Oilseed rape cv. Zheyouyou 2 was grown in 10 field experiments in Zhejiang province, south-east China, with B rates from 0 to 3· 3 kg/ha. At 4 of the sites, oilseed rape was resown in the following year to assess seasonal effects on critical concentrations. Experiments were conducted on the 3 main soil groups on which oilseed rape is grown in south-east China. The youngest open leaf (YOL) was selected as the sampling part because its B concentrations were strongly responsive to increasing B supply and well correlated with seed yield response. In this study, the best model of the relationship between YOL B concentration and yield was the Mitscherlich equation, which explained 68-89% of the variation in the data. The calculated critical range in the YOL at seedling stage was 20-25 mg B/kg and appeared to be valid in 2 seasons and on 3 soil types. The critical B range for prognosis of B deficiency was found to predict consistently those crops in farmers" fields that had low seed yield and low soil B, but needs to be evaluated in other growing environments especially those for spring rape.

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Prognosis of Boron Deficiency in Oilseed Rape (Brassica napus) by Soil Analysis

Boron in Plant and Animal Nutrition ◽

10.1007/978-1-4615-0607-2_30 ◽

2002 ◽

pp. 311-317

Author(s):

Youzhang Wei ◽

Richard W. Bell ◽

Yuai Yang

Keyword(s):

Brassica Napus ◽

Oilseed Rape ◽

Soil Analysis ◽

Boron Deficiency

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The importance of sampling immature leaves for the diagnosis of boron deficiency in oilseed rape (Brassica napus cv. Eureka)

Plant and Soil ◽

10.1007/bf00011434 ◽

1996 ◽

Vol 183 (2) ◽

pp. 187-198 ◽

Cited By ~ 29

Author(s):

Longbin Huang ◽

Zhengqian Ye ◽

Richard W. Bell

Keyword(s):

Brassica Napus ◽

Oilseed Rape ◽

Boron Deficiency

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Interactive Regulation of Hormone and Resistance Gene in Proline Metabolism Is Involved in Effector-Triggered Immunity or Disease Susceptibility in the Xanthomonas campestris pv. campestris–Brassica napus Pathosystem

Frontiers in Plant Science ◽

10.3389/fpls.2021.738608 ◽

2022 ◽

Vol 12 ◽

Author(s):

Md Al Mamun ◽

Md Tabibul Islam ◽

Bok-Rye Lee ◽

Dong-Won Bae ◽

Tae-Hwan Kim

Keyword(s):

Brassica Napus ◽

Binding Site ◽

Xanthomonas Campestris ◽

Disease Susceptibility ◽

Proline Accumulation ◽

R Gene ◽

R Genes ◽

Proline Metabolism ◽

Leucine Rich Repeat ◽

Effector Triggered Immunity

To characterize cultivar variations in hormonal regulation of the transition between pattern-triggered immunity (PTI) and effector-triggered immunity or susceptibility (ETI or ETS), the responses of resistance (R-) genes, hydrogen peroxide, and proline metabolism in two Brassica napus cultivars to contrasting disease susceptibility (resistant cv. Capitol vs. susceptible cv. Mosa) were interpreted as being linked to those of endogenous hormonal levels and signaling genes based on a time course of disease symptom development. Disease symptoms caused by the Xanthomonas campestris pv. campestris (Xcc) infections were much more developed in cv. Mosa than in cv. Capitol, as shown by an earlier appearance (at 3 days postinoculation [3 DPI]) and larger V-shaped necrosis lesions (at 9–15 DPI) in cv. Mosa. The cultivar variations in the R-genes, hormone status, and proline metabolism were found in two different phases (early [0–3 DPI] and later [9–15 DPI]). In the early phase, Xcc significantly upregulated PTI-related cytoplasmic kinase (Botrytis-induced kinase-1 [BIK1]) expression (+6.3-fold) with salicylic acid (SA) accumulation in cv. Capitol, while relatively less (+2.6-fold) with highly increased jasmonic acid (JA) level in cv. Mosa. The Xcc-responsive proline accumulation in both cultivars was similar to upregulated expression of proline synthesis-related genes (P5CS2 and P5CR). During the later phase in cv. Capitol, Xcc-responsive upregulation of ZAR1 (a coiled-coil-nucleotide binding site-leucine-rich repeat [CC-NB-LRR-type R-gene]) was concomitant with a gradual increase in JA levels without additional proline accumulation. However, in cv. Mosa, upregulation of TAO1 (a toll/interleukin-1 receptor-nucleotide binding site-leucine-rich repeat [TIR-NB-LRR-type R-gene]) was consistent with an increase in SA and abscisic acid (ABA) levels and resulted in an antagonistic depression of JA, which led to a proline accumulation. These results indicate that Xcc-induced BIK1- and ZAR1-mediated JA signaling interactions provide resistance and confirm ETI, whereas BIK1- and TAO1-enhanced SA- and/or ABA-mediated proline accumulation is associated with disease susceptibility (ETS).

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